Process and Steps
What Happens on Completion Day, and What You Need to Do
Completion is the day the keys and the legal title actually change hands. It is a single working day, but the choreography matters. Here is what actually happens, what your solicitor handles for you, and what you need to do yourself.
A Single Day, with a Lot Going On
Completion is the day the sale actually finishes. The keys, the legal title and the money all change hands inside a few hours. Most sellers spend a long time getting to this point and then discover, slightly to their surprise, that completion arrives without much drama. Almost all of the work was done before exchange, and the solicitor handles the remaining steps behind the scenes between exchange and completion. On the day itself, the buyer arrives at the agent's office to collect the keys and the seller's job is mainly to be ready to leave on time.
The choreography matters because timing is tight. Banks have cut-off times for the kind of large same-day payments used in conveyancing. Chains can have four or five transactions stacking up, each waiting for the one below. Most completions go through without a hitch, but when they do not, the cause is almost always a timing problem rather than a deeper one, and almost all of them resolve themselves with patience.
This guide walks through what completion day actually looks like, the cut-off times that matter, what the seller needs to do and the leasehold-specific steps that follow. There is also a section on what can go wrong, a short tips list for a clean handover and a list of the legislation behind it all.
The Difference Between Exchange and Completion
It is worth being clear about the two moments because they often get blurred in conversation. Exchange of contracts is when both sides become legally bound. The signed contracts are physically (or electronically) exchanged between the two solicitors, the buyer's deposit is released, and the completion date is fixed. From exchange onward, neither side can walk away without breaching the contract. Completion is the day the rest of the purchase money moves, the legal title transfers from seller to buyer and the keys change hands.
Exchange and completion are usually 1 to 4 weeks apart. Two weeks is the most common gap; it gives the buyer's solicitor time to sort the mortgage advance, finalise pre-completion searches and prepare the completion statement. Same-day exchange and completion does occasionally happen on a straightforward cash sale with no chain, but it is the exception rather than the rule. Auction sales are different again: contracts exchange at the fall of the hammer and completion is typically 28 days later under the auctioneer's general conditions. For most chained leasehold sales the 1 to 4 week gap is intentional. A longer gap (3 to 4 weeks) is sometimes negotiated where one party needs more time to coordinate moving arrangements, and a shorter gap (5 to 7 days) is sometimes possible for a buyer who is keen to move in.
Once the date is fixed at exchange, it is in the contract. Either side can ask to vary it after exchange, but the other side does not have to agree, and a unilateral failure to complete on the agreed day triggers compensation under the contract terms. In practice, requests to push back by a day or two are usually granted by mutual agreement; longer postponements are harder.
What Actually Happens on the Day
Completion happens through a sequence of solicitor-to-solicitor steps that are largely invisible to the seller. Knowing the order helps make sense of the silence.
1. Buyer's solicitor sends the completion monies
The buyer's solicitor receives the balance of the purchase price from the buyer (the headline price less the deposit already paid at exchange) and the mortgage advance from the buyer's lender, and sends the lot, by CHAPS, to the seller's solicitor's client account. CHAPS is a same-day high-value transfer system used across UK conveyancing because it is final once received. Faster Payments is sometimes used for small amounts but CHAPS is the standard for completion monies. The transfer typically goes out mid-morning to ensure it arrives before the bank's afternoon cut-off.
2. Seller's solicitor confirms receipt
Once the funds land, the seller's solicitor calls or emails to confirm completion. This is the moment the legal title is treated as transferred. The seller's solicitor will usually call the estate agent to authorise key release, and call or email the seller to confirm the sale has completed.
3. Title transfer (TR1) is dated
The TR1 is the formal HM Land Registry transfer document that conveys the title from seller to buyer. Both parties sign it before completion (the seller a few days earlier, the buyer typically on completion day). The buyer's solicitor dates the TR1 with the date of completion, which is the document later submitted to HM Land Registry to register the new owner.
4. Seller's mortgage redeemed
If the seller had a mortgage on the flat, the seller's solicitor pays off the outstanding balance directly to the lender out of the completion monies. The lender provides a redemption statement a few days before completion showing the exact figure due on the completion date (it includes daily interest up to the date the funds clear). Once the lender confirms receipt, it issues a DS1 form (or its electronic equivalent) which the buyer's solicitor uses to remove the seller's charge from the register as part of the post-completion registration application.
5. Keys released to the buyer
The estate agent (or whoever holds the keys; in a private sale the seller's solicitor will arrange this) releases the keys to the buyer. By convention this is in person at the agent's office, although where the agent and the property are far apart the buyer sometimes collects from the property itself. Keys must never be released before the seller's solicitor has confirmed completion.
6. Seller's solicitor sends the balance to the seller
After paying off the seller's mortgage, settling the estate agent's commission, settling the solicitor's own fees and any service charge arrears, the solicitor sends the remaining balance to the seller's nominated account. CHAPS or Faster Payments; usually same day if completion is before mid-afternoon.
Steps 1, 2 and 3 happen within minutes of each other once the buyer's solicitor pulls the trigger on the CHAPS transfer. Step 4 (mortgage redemption) and step 6 (seller balance) follow within the same working day. Steps 7 onward (SDLT, registration, Notice of Transfer) happen in the days and weeks after completion and are covered later in this guide.
The Cut-Off Times That Matter, and Why Completion Sometimes Fails on the Day
The two cut-off times that shape completion day are the contractual completion time and the bank's CHAPS cut-off. Both can move depending on the contract and the bank, but the rough numbers are similar across most transactions.
The contractual completion time
The contract sets a default time of completion. Under the Standard Conditions of Sale (5th edition), the residential conveyancing template most contracts use, money received after 2pm is treated as if completion happened the next working day. To leave a safety margin against this, many contracts (particularly in chains) specify 12 noon or 1pm as the contractual completion time. Whatever time the contract specifies is the time the buyer is entitled to take possession and the time by which the seller has to be out.
The bank's CHAPS cut-off
UK retail and high-street banks process CHAPS transfers up to a daily cut-off, typically between 3pm and 5pm, with internal cut-offs an hour or two earlier. After cut-off the transfer slips to the next working day, which means completion slips. Solicitors aim to start sending the completion monies in the morning, so chains nearly always finish well before any cut-off becomes a worry. Where a chain runs late, the worry is real: a 4pm CHAPS missed by the bank's risk-check department can mean an overnight delay.
Why completion sometimes fails on the day
Most failed completions fail for one of a small number of reasons:
- Chain delay above the seller. Whoever is buying the seller's onward property has not yet received their completion monies and cannot release them. The seller waits.
- Bank fraud check on the CHAPS transfer. Large transfers between unfamiliar accounts trigger automated checks that can hold the funds for several hours.
- Missing or incorrect mortgage redemption figure. If the lender has not yet supplied the seller's solicitor with the exact figure to discharge the seller's mortgage, the solicitor cannot release the funds onward.
- Mortgage advance not yet released to the buyer's solicitor. The buyer's lender is meant to send the mortgage funds to the buyer's solicitor the day before or on the morning of completion; occasionally there is a delay at the lender's end.
- Last-minute disagreement over fixtures or condition. Rare, but it happens. The buyer arrives, finds an item missing that they expected to be there, and refuses to take possession until it is sorted.
If completion does fail on the day, the contract terms on late completion start to apply. Under the Standard Conditions, the defaulting party (whichever side did not perform) becomes liable for compensation at the contract rate of interest on the price for each day of delay. After 10 working days of unresolved delay, either side can serve a Notice to Complete, which is the formal demand to complete within 10 working days of the notice or face the contract being rescinded with damages. In practice, these provisions are rarely needed: most delays resolve within 24 hours.
What the Seller Needs to Do
The seller's role on completion is mostly practical: get the flat ready, vacate on time and let the solicitors do the legal work. The points below are split into the day before, the morning of and the day itself.
The day before completion
- Take final meter readings (gas, electric, water if individually metered). Photograph the meter dials so the readings are dated and uncontestable.
- Confirm with your solicitor what time completion is expected and how you will hear when it has happened. A phone call is usual; some firms email.
- Notify Royal Mail of redirection. The standard Royal Mail redirection service starts at £45 for 3 months; longer periods are available. Worth doing because some letters (HMRC, your bank, the freeholder) may take weeks or months to reach the new address otherwise.
- Pack remaining essentials. Anything not listed in the fixtures and fittings form (the TA10) as included in the sale is yours to take.
- Confirm the key handover plan with the estate agent. Where will you drop the keys, and at what time?
The morning of completion
- Vacate by the contractual time. If the contract says 1pm, the flat needs to be empty (and clean enough not to be a complaint) by then.
- Final walk-through. Check the flat is empty, that nothing has been overlooked in storage cupboards or the loft and that any items listed as included (curtain rails, the boiler manual, kitchen appliances) are still there.
- Photograph the meters again for final-final readings.
- Drop the keys at the estate agent's office. Hand all sets to the agent, including communal keys and fobs (covered in the next section). Get a receipt or email confirmation that they have all the keys.
- Leave the flat clean and tidy. The contract usually requires "broom clean" condition; a quick hoover and wipe of surfaces meets that. Leaving the flat in a state can trigger a complaint and damage the seller's relationship with the buyer for any post-completion issues.
Later that day, once completion is confirmed
- Confirm completion with your solicitor. They will call when the funds arrive.
- Notify the utilities (gas, electric, water) of the move and supply the final meter readings.
- Notify the council for council tax. Most councils have an online "moving home" form.
- Notify the TV licence, broadband, contents insurance. Cancel or transfer to the new address.
- Send a courtesy email to the managing agent letting them know the flat has sold, with the completion date, the buyer's solicitor's name and (if you have it) the buyer's contact details. The formal Notice of Transfer is served by the buyer's solicitor in the days after completion, but a courtesy email speeds up the managing agent's transfer of service charge invoicing to the new leaseholder.
Leasehold-Specific Steps After Completion
A leasehold sale has a handful of extra steps that a freehold sale does not. Most happen at solicitor level in the days after completion and the seller has nothing to do beyond sending the courtesy email mentioned above. Worth knowing what is happening behind the scenes.
Notice of Transfer
The lease almost always requires the buyer to give written notice to the freeholder (and any management company) that the flat has changed hands. The lease specifies the time within which the notice must be served, typically 1 month from completion. The buyer's solicitor handles this. The freeholder or managing agent charges a fee for processing the notice, typically £50 to £250 plus VAT, sometimes more in a managed development. The fee is the buyer's cost on the new lease, paid out of the buyer's funds at completion or invoiced to the buyer afterwards. The seller is not normally on the hook for it, although in some cases a small admin charge from the managing agent for closing the seller's service charge account does appear on the seller's completion statement.
Notice of Charge
If the buyer is taking out a new mortgage on the flat, the lease usually also requires written notice of the new charge. Same process as the Notice of Transfer; a separate fee is sometimes charged or the two can be combined. Again, the buyer's solicitor handles this.
Service charge apportionment
Service charge is typically billed in advance, often quarterly or half-yearly. If the seller has paid the most recent demand and completion happens part-way through the period, the buyer reimburses the seller for the unused portion at completion. The seller's solicitor calculates this on the completion statement based on the latest service charge demand and the management pack figures. If there are arrears, those are paid out of the seller's proceeds before the balance is sent on. The arrears figure is supplied by the managing agent shortly before completion.
Apportionment of ground rent
If the flat still pays a ground rent, that is also apportioned at completion in the same way as service charge. Most modern leases pay a peppercorn (zero) ground rent under the Leasehold Reform (Ground Rent) Act 2022; older leases still have a positive ground rent that needs apportioning. The figures are usually small.
Year-end balancing charge retention
Service charge accounts are usually reconciled annually: the freeholder or managing agent works out actual costs against estimated costs and either issues a balancing charge for any shortfall or credits any surplus. Where a balancing charge could fall in the months after completion against expenditure incurred while the seller was the leaseholder, the buyer's solicitor sometimes asks for a small retention from the seller's funds to cover it. The retention is held in client account and released to the seller once the year-end accounts are finalised, usually a few months later. Whether a retention is asked for depends on the lease, the timing within the service charge year and the parties' negotiating position; not every sale has one.
Reserve and sinking fund balances
Reserve fund balances (sometimes called sinking funds) stay with the freeholder or managing company; they are not transferred between seller and buyer. The fund belongs to the building, not to the individual leaseholders. The seller does not get a refund of their past contributions and the buyer does not pay extra for the existing balance.
Communal keys and access cards
Many flats come with more than the front-door key: communal entry fobs, post-box keys, parking permits, parking-bay or bike-store cards, electric-charging cards, lift override keys. All of these need to be handed over to the buyer through the agent. The TA10 fixtures and fittings form usually lists what is included; if any items are missing, the managing agent sells replacements (often expensive on premium developments) and the buyer can claim the cost from the seller as a breach of the contract terms.
Where the Money Goes (and What Comes Off the Top)
The buyer's solicitor sends the completion monies (the balance of the purchase price plus any agreed apportionments) to the seller's solicitor. The seller's solicitor then deducts a number of items before the balance reaches the seller. Knowing what comes off the top makes the final completion statement easier to read and avoids the surprise of the net figure being lower than expected.
What comes off the top, in order
- Mortgage redemption. If the seller has a mortgage on the flat, the outstanding balance plus daily interest up to completion is paid directly to the lender. The lender's redemption statement obtained a few days before completion shows the exact figure.
- Estate agent's commission. Typically 1 to 2 percent plus VAT of the sale price. The agent will have sent the invoice to the seller's solicitor before completion; the solicitor pays it from the proceeds.
- Seller's solicitor's fees and disbursements. Conveyancing fee plus VAT, plus disbursements (any title search fees, the cost of the LPE1 management pack if the seller paid for it directly, official copies, etc.).
- Service charge or ground rent arrears. Settled with the managing agent or freeholder out of completion proceeds.
- Service charge year-end retention (where applied) held back temporarily.
- Any agreed price reduction or retention from earlier negotiation. If a survey-stage retention was agreed for outstanding works, that is held back in client account pending the condition.
- Any redemption-related early-repayment charges from the seller's lender. If the seller's mortgage was inside its early repayment window, the ERC is deducted at the same time as the redemption.
What is left for the seller
The balance is the seller's net proceeds. The solicitor sends a final completion statement showing the headline price, every deduction and the final figure, then transfers the funds to the seller's nominated account. CHAPS arrives within a few hours; Faster Payments usually within minutes. Where completion happens late in the day, the balance can land the following working day.
Stamp Duty Land Tax (the buyer's responsibility, not the seller's)
SDLT is paid by the buyer, not the seller. The buyer's solicitor files the SDLT return and pays the tax to HMRC within 14 days of completion. The buyer cannot register the transfer at HM Land Registry without an SDLT certificate, so the SDLT step is part of the buyer's post-completion process. The seller has nothing to do with SDLT, but it is worth knowing the timeline so that an apparent delay on the buyer's side after completion does not come as a surprise.
What Can Go Wrong on Completion Day
Most completions go through without incident. When they do not, the cause is almost always a timing problem rather than something deeper, and the answer is almost always patience while the solicitors work it out. The points below are the failure modes that come up most often and what the seller can usefully do about them.
The funds have not arrived by mid-morning
This is normal in chains. The seller is waiting on the buyer's solicitor; the buyer's solicitor is often waiting on a sale higher up the chain. The seller's solicitor is usually in close contact with the buyer's solicitor and will know when the funds are expected. Useful action: check in with the seller's solicitor by mid-morning. Useless action: phoning the agent every 20 minutes.
The funds have not arrived by 2pm
Now it matters. Under the Standard Conditions, money received after 2pm is treated as if completion happened the next working day, which can trigger compensation for late completion. The seller's solicitor will be on the phone to the buyer's side trying to identify the blocker. Common blockers at this stage: a CHAPS transfer held up by a bank fraud check, a chain transaction that has stalled, the buyer's lender having released the mortgage advance late.
Completion does not happen at all on the day
The contract terms on late completion start to apply. Interest accrues at the contract rate against the defaulting party for each day of delay. After 10 working days, either side can serve a Notice to Complete: a formal notice giving the other side 10 working days to complete or face the contract being rescinded with damages payable. In practice, Notices to Complete are rarely needed; most failures resolve themselves within a working day or two.
Last-minute disagreement over fixtures and fittings
Occasionally the buyer arrives, finds an item missing that they expected to be included, and refuses to take possession or threatens to. The TA10 fixtures and fittings form completed early in the conveyancing is meant to prevent this, but ambiguities do arise. Useful action: keep a copy of the TA10 to hand. If the buyer's complaint is justified, the seller can usually defuse it with a small price reduction or by agreeing to replace the item; if it is not justified, the seller's solicitor handles the rebuttal.
Keys not where they should be
Less common than it sounds, but it does happen: keys left at the wrong agent's branch, posted in the wrong post-box, taken home by mistake. Avoidable with a clear plan agreed the day before and with a receipt at handover.
The buyer requests delay because of a personal issue
A removal van breakdown, a family emergency, a nursery booking. The seller does not have to agree to a delay, but the relationship is usually better served by accommodating where possible (a few hours, occasionally a day). Anything longer needs a formal contract variation through the solicitors and is not the seller's obligation.
Practical Tips for a Smooth Handover
Most of these are small. Together they make completion day quieter, save the seller from chasing things later and avoid the kind of low-grade dispute that occasionally surfaces in the weeks after completion.
- Take meter readings the morning of completion and photograph them, then again as you leave. Two photos timestamped a few hours apart cover any utility-company query.
- Bag and label all keys: front-door, back-door, communal entry fob, post-box, parking permit. A simple note saying which key is which saves the buyer a frustrating evening.
- Leave appliance manuals, the boiler manual, parking instructions and any communal-area information for the buyer in a kitchen drawer. Even a short note with the freeholder's name and the managing agent's contact details is genuinely useful.
- Email the managing agent on the morning of completion: "The flat has completed today. New leaseholder details will follow from their solicitor. Please redirect any service charge invoicing." Saves the buyer a delay at the managing agent's end.
- Cancel direct debits for utilities and council tax the day after completion, not before. Cancelling early can leave a gap that triggers a "missed payment" letter.
- Get the keys to the agent before the contractual completion time, not after. Late keys can mean the buyer cannot move in on the day even though the funds have cleared.
- Leave a forwarding address on the kitchen counter or the front-door mat. Royal Mail redirection covers post addressed to you, but the buyer often gets ad-hoc post (the freeholder, the council, the previous decade of magazine subscriptions) and a forwarding address saves them ringing the agent in three weeks' time.
- Ask your solicitor for an estimated completion statement a week before completion so you can see the net figure ahead of time. The estimate is rarely off by more than a few pounds.
- Confirm with the agent who the buyer is and how the keys will be released. Handing over to the right person matters; a polite but firm question on the morning of completion is reasonable.
Relevant Legislation
Five pieces of law and one set of standard contract terms sit behind completion day in England and Wales.
The Standard Conditions of Sale (5th edition, 2018), published by the Law Society, are the standard contract terms most residential conveyancing contracts incorporate. They set the default time of completion (money received after 2pm is treated as next-day), the rules on apportionment of outgoings and ground rent, the contract rate of interest for late completion, and the Notice to Complete provisions.
The Law of Property Act 1925, section 47 sits in the background for the rare case where a property is destroyed or damaged between exchange and completion: where the seller had insurance on the property, the insurance proceeds pass to the buyer on completion. On a leasehold flat the buildings insurance is normally arranged by the freeholder under a block policy, so this section rarely arises. The seller's general duty between exchange and completion (to keep the property in the condition it was at exchange) sits in the contract terms themselves rather than in section 47.
The Land Registration Act 2002 governs the registration of the disposition. The buyer's solicitor obtains an OS1 priority search before completion, which gives a 30-working-day window during which the application to register the transfer must be lodged with HM Land Registry. The TR1 transfer document, the AP1 application, the SDLT certificate and the lender's charge form are sent in together. Until the registration completes, the buyer holds an equitable interest; once registered, legal title transfers formally.
The Finance Act 2003 and the Stamp Duty Land Tax regulations made under it set the buyer's SDLT obligation. The buyer must file an SDLT return and pay the tax within 14 days of the effective date of the transaction (which is normally completion). The seller has no SDLT role on a sale.
The lease itself sets out most of the leasehold-specific completion-day points: the timing for Notice of Transfer and Notice of Charge, the freeholder's processing fee, the apportionment of service charge and ground rent. Lease drafting historically references the Landlord and Tenant Act 1985 and the Landlord and Tenant Act 1987, both of which sit in the background of how managing agents operate and how service charges are demanded.
The Leasehold and Freehold Reform Act 2024 contains a number of provisions that will affect leasehold sales but not the mechanics of completion day. The two-year ownership rule for lease extensions was abolished from 31 January 2025, so a buyer can now serve a Section 42 notice to extend the lease immediately after completion if they wish; that is something the buyer thinks about, not the seller.
Further Reading
Two adjacent guides cover what comes immediately before completion: handling the buyer's survey, and what to do if the sale falls through before exchange.
Frequently Asked Questions
There is no single time. The contract sets a default, often 1pm or 2pm. The Standard Conditions of Sale (5th edition) treat money received after 2pm as if completion happened the next working day, so most contracts work back from that to give a safety margin. In practice, the funds usually arrive at some point during the morning or early afternoon. In a chain, the timing is set by whichever transaction is last in the sequence: a one-link chain can complete by 11am; a four-link chain can run until 3pm or beyond, with the seller waiting longer than they expected.
Yes, by the time stated in the contract for completion. The default position is that the buyer is entitled to take possession from the contractual time on completion day, so the flat needs to be empty by then. The most common contract time is 1pm, sometimes 2pm. Practically, sellers vacate by mid-morning, drop the keys at the estate agent's office and leave the flat ready for the buyer. Late vacation can lead to a compensation claim from the buyer for any costs the delay causes (removal vans waiting, hotel nights, etc.).
Wait, and let the solicitors talk to each other. Most late completions resolve themselves within a few hours: a CHAPS payment held up by a bank's fraud check, a chain transaction higher up the line that was slow to release, or a missing redemption figure from the buyer's lender. The seller's solicitor monitors the position and chases. If the funds still have not arrived by the end of the working day, completion rolls to the next working day and the contract terms on late completion start to apply: interest at the contract rate accrues against the defaulting party, and after 10 working days either side can serve a Notice to Complete to force the issue. In practice, a Notice to Complete is rarely needed; most delays are resolved within the day or the day after.
The buyer, in almost every case. The Notice of Transfer (and Notice of Charge if the buyer is taking out a new mortgage) is a step the new leaseholder is required to give to the freeholder under the lease, formally registering them as the new owner. The freeholder or managing agent charges a fee for processing the notice, typically £50 to £250 plus VAT, sometimes more in larger blocks or higher-end developments. The fee is the buyer's cost on the new lease, paid by the buyer's solicitor out of the buyer's funds. The seller normally has no role beyond letting the managing agent know the flat has changed hands; the formal notice is served by the buyer's solicitor.
It is sorted between the two solicitors as part of the completion accounts. The seller's solicitor obtains a service charge balance from the managing agent shortly before completion. If the seller has paid in advance and there is a credit, the buyer reimburses that share at completion (it is added to the price). If there are arrears, those are paid out of the seller's proceeds before the balance is sent on. Year-end reconciliations are slightly different: where a balancing charge could fall due in the months after completion, solicitors sometimes hold a small retention from the seller's funds to cover it, releasing the balance to the seller once the year-end accounts are settled. The mechanics happen at solicitor level, but it is worth asking your solicitor what apportionment is being applied so you understand the final figure on the completion statement.
Via the estate agent in almost every case. The agent holds the keys until completion is confirmed by the seller's solicitor, then releases them to the buyer. That sequence matters: keys must not pass to the buyer before the seller's solicitor has confirmed receipt of the completion monies, otherwise the seller could find themselves having vacated and handed over a flat they have not yet been paid for. If there is no agent involved (a private sale or a direct sale to a cash buyer), the seller's solicitor will tell the seller exactly when to release the keys, usually after a phone call or email confirmation that the funds have cleared. Sellers should never give the buyer keys early, even if asked.
On a leasehold flat, the buildings insurance is normally arranged by the freeholder or managing agent through a block policy, paid for by leaseholders through the service charge. The seller does not need to cancel anything: the cost simply transfers to the buyer through the service charge from completion. Contents insurance is the seller's own policy and should be cancelled or transferred to the new address from completion day. If the seller has a separate buildings policy (uncommon on a flat but possible on a small purpose-built block where the leaseholders insure individually), that needs to be cancelled or transferred, normally with effect from completion. Worth asking the insurer for a part-year refund if applicable.
Usually the same working day if completion is before mid-afternoon. The seller's solicitor receives the completion monies, deducts the various costs (mortgage redemption, estate agent commission, solicitor's fees, any service charge arrears, any retention for year-end reconciliation), and sends the balance on to the seller's nominated account by CHAPS or Faster Payments. CHAPS arrives within hours; Faster Payments usually within minutes. Where completion happens late in the day or close to a bank cut-off, the balance can land the next working day. The seller will get a final completion statement from the solicitor showing exactly what came off the top and what was paid out.
No. Once contracts have exchanged and completion has happened, the sale is final and there is no statutory right for either side to back out. That is true across all property sales in England and Wales, leasehold or freehold. The cooling-off rights that exist for some consumer contracts (distance and off-premises contracts under the Consumer Contracts Regulations 2013) do not apply to a property transaction. After completion, any disputes are resolved through the contract terms and the law of property, not through cancellation. In practice, sellers occasionally find a buyer raising a small issue post-completion (a missing key, a forgotten utility account); these are nearly always settled informally rather than escalated.
Not a disaster, but worth fixing the same day if you can. Utility companies allow customers to submit readings online or by phone for a few days after a move; ring them with the reading the day after completion if you missed it on the day itself. If you genuinely cannot get back into the flat to read the meters, the utility company will estimate the bill based on previous usage and the seller can dispute it later if it looks wrong. A photograph of the meter dials taken during the final walk-through is the simplest evidence; many sellers also note the readings on a pad and leave a copy for the buyer in the flat.