Completion dates · exchange · certainty

Can you guarantee a completion date when you sell a house?

On the open market, honestly: no. A completion date only becomes legally binding at exchange of contracts — months into the process — and roughly one agreed sale in four never gets there. A date can be guaranteed earlier, but only by a buyer who signs up to it in the contract, with money attached to being late. This page explains all three routes that do that, including the two that aren’t us.

Exchange daythe only moment a completion date becomes legally binding in an open-market sale — typically three to four months after an offer is accepted

~1 in 4agreed sales that collapse before completion — broken chains and failed mortgages, mostly (industry data)

£500 a daywhat a guaranteed date should cost the buyer who misses it — it’s what we owe you if we’re late (capped, and subject to contract)

Why the open market can’t promise you a date

It isn’t anyone’s fault; it’s the design. An accepted offer starts a process — searches, surveys, mortgage underwriting, and the same steps again for every link in the chain — in which nobody is committed to anything until everybody exchanges at once. Finding a buyer takes about 40 days on national averages; offer to completion runs five to six months end to end; and until the day contracts are exchanged, any party can change the date, renegotiate, or leave. The completion date you and your buyer “agreed” in week one is a hope with a calendar entry.

Exchange is where that flips. From exchange, the date in the contract is enforceable: miss it and a notice to complete follows, interest runs, deposits are at risk. Which is why the honest version of the question isn’t “can I get a guaranteed completion date?” but “how early can I get to a binding contract — and what does that cost?”

The three routes to a date that’s actually fixed

All three are legitimate. They differ in when the contract binds, and what the certainty costs.

Open market, driven hard

Best price, no guarantee — but you can shorten the odds: a chain-free or cash buyer, a proactive solicitor instructed on day one, searches ordered early, and a short exchange-to-completion gap agreed up front. If your deadline is six months out and the market is moving, this is usually the right call and we’ll say so.

The date still binds only at exchange, months in — and about a quarter of agreed sales never reach it. If the deadline is real, you need a plan for the day this one slips.

Auction

Exchange happens the moment the hammer falls, and completion follows on a fixed timetable — typically 28 days. That is a genuinely guaranteed date, and for some properties the room bids well. We explain it properly on how auctions work, and we’ll refer you to one when it’s the better route.

The date is certain; the price isn’t — it’s decided on the day. Add entry lead time (usually four to six weeks before the sale), fees, and the risk of no sale if the reserve isn’t met.

A contracted buyer — us

You pick the completion date first — from seven days out to six months — and the contract is built backwards from it. The price is fixed in writing before you commit, and if we complete late, we pay you £500 a day (capped, and subject to contract). The date isn’t a hope with a calendar entry; it’s the clause the deal hangs off.

The price is below market value — roughly 65% for about a week, 73% at two to four weeks, up to 82% flexible — shown and explained on how the price works before you give us anything.

Certainty priced openly, instead of promised loosely.

Work backwards from your date

Put in the day you actually need this done by. It answers the only question that matters: which routes are still open?

Whatever buyer you use: what “guaranteed” has to mean

The word is cheap; the clause isn’t. If any buyer — including us — tells you your date is guaranteed, the guarantee is only as real as what’s written down. Ask for four things: the completion date in the contract itself, not a covering email; a daily payment for lateness with the amount and the cap stated; the price fixed in writing with the conditions under which it could change listed exhaustively (ours: it doesn’t, once locked — see the price-lock promise); and proof of funds, because a guarantee from a buyer who hasn’t shown they can complete is decoration. A buyer who resists any of the four is telling you something useful early, which is the cheapest time to learn it.

Sources: MoneyHelper, exchange and completion · Property Solvers, exchange-to-completion timing · Ready Steady Sell, UK selling statistics (time-to-buyer ~40 days, ~5–6 months end to end, ~1 in 4 fall-throughs) · Clive Emson, when a buyer pulls out. England & Wales conveyancing; Scotland binds earlier via missives. General information, not legal advice. Last reviewed September 2026.

The questions people ask about completion dates

Going deeper on one part? Each has its own page: who decides the completion date · how long between exchange and completion · what happens when completion is late.

Who decides the completion date when you sell a house?

Nobody, unilaterally — it's negotiated between every buyer and seller in the chain and only becomes legally binding when contracts are exchanged. Until exchange, any date anyone has mentioned is an intention, not a commitment, and either side can move it or walk away without penalty.

How long is there between exchange and completion?

Commonly one to two weeks, by agreement — it can be the same day, though same-day exchange-and-complete leaves no safety margin, or months if both sides want a long stop. The reliable part is what comes before it: getting a typical sale from offer to exchange takes roughly three to four months of conveyancing, searches and mortgage work.

What happens if completion is delayed?

The defaulting side can be served a notice to complete, usually giving ten working days, with interest running at the contract rate — and a buyer who still fails to complete can lose their deposit. That machinery only exists after exchange. Before exchange there is no penalty for delay at all, which is why open-market timescales drift.

Can an estate agent guarantee a completion date?

No. An agent markets the property and manages the chain, but can't legally bind a buyer to a date — only exchanged contracts do that. An agent saying a buyer “wants to complete in eight weeks” is passing on an intention. It's often sincere. It's never enforceable.

Is a guaranteed completion date worth accepting a lower price?

It's a trade, and it should be written down as one: our bands run from about 65% of market value for completion in about a week to about 82% with a flexible date. If you have no deadline, take the open market and the better price. The maths favours certainty when a fixed date protects something bigger — an onward purchase, a repossession hearing, a job that starts abroad, a chain that already collapsed once.

Name the date. We’ll put a figure on it.

There's no obligation and nothing to sign. We'll give you a figure in writing, with our reasoning, and you can take it to anyone you like before you decide.

Or call us: 0191 249 3969 · 8am–8pm, seven days

Selling more than one — or the whole building? See blocks of flats and commercial property.

Deadline coming from a sale that just collapsed? Start at buyer pulled out. Choosing the date itself is explained on you choose the date.