Property Fundamentals
What happens on exchange and completion?
Exchange of contracts is the moment a property purchase becomes legally binding in England, Wales and Northern Ireland. Both conveyancers read out identical signed contracts over the phone, the buyer's deposit (usually 10%) is sent, and a completion date is fixed. After exchange neither side can withdraw without paying damages.
Completion is the day legal ownership transfers and you get the keys. The buyer's conveyancer sends the balance of the purchase price by CHAPS to the seller's conveyancer, the seller's lender's mortgage is redeemed, and the seller's conveyancer authorises the estate agent to release keys. MoneyHelper describes the standard order of events.
Within 14 days of completion the buyer's conveyancer files the SDLT return and pays any duty via GOV.UK. HM Land Registry then registers the new owner — currently a 3–6 month backlog for first registrations, faster for transfers of registered titles.
What this means in practice
A buyer in Bristol BS6 exchanges on a £420,000 terrace at 14:30 on Friday 6 March 2026 with completion fixed for Friday 20 March. They send a £42,000 deposit by Faster Payment that afternoon. On the morning of the 20th, their conveyancer drawdowns £378,000 from the lender at 09:45 and CHAPS the full balance to the seller's solicitor by 11:00. Keys are released at 13:30. The SDLT return (duty of £8,500) is filed on 28 March, well within the 14-day window. Land Registry receives the AP1 application on 30 March; the new title appears on the public register on 4 August — 18 weeks later.
Related questions
Can exchange and completion happen on the same day?
Yes. Same-day exchange and completion is common with cash buyers, auction purchases and chain-free transactions where speed matters. The risk is that any last-minute hitch — a missing signature, a delayed mortgage drawdown, a CHAPS cut-off after 15:00 — knocks the whole deal into the next working day, with no contract in place to bind either party. Lenders sometimes refuse to release funds on the same day because they need 24 hours to action a Certificate of Title. For most chain transactions, a 1–4 week gap between exchange and completion is the norm.
What happens if I miss the completion date?
The standard contract incorporates the Standard Conditions of Sale, under which the non-defaulting party can serve a Notice to Complete giving 10 working days to perform. If the buyer fails to complete inside that window the seller can rescind, keep the 10% deposit and resell, suing for any shortfall plus interest at typically 4% above base rate. If the seller is the defaulting party, the buyer recovers the deposit with interest and any wasted costs. Late-completion interest accrues daily from the contractual date, so even a one-day slip adds up on a £500k purchase.
Sources
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