Gazumping: what it is, why it's legal, and how to protect yourself

In England, Wales and Northern Ireland, having an offer accepted creates no legal commitment on either side. The sale only becomes binding when contracts are exchanged, which usually happens 8 to 12 weeks after the offer is accepted — sometimes longer if there's a chain or conveyancing delays. During that whole window, the seller is free to accept a better offer from someone else.

Gazumping is most common when prices are rising quickly or when a sale drags on. A rival buyer might offer more money, but sellers also switch for speed: a chain-free buyer with cash or a mortgage ready to go can 'gazump' you even with a similar offer. Estate agents are legally required to pass every offer to the seller right up until exchange, so interest from other buyers doesn't stop just because your offer was accepted.

The financial sting is real. By the time a purchase falls through you may have already paid for a survey, conveyancing searches and mortgage arrangement — several hundred to a few thousand pounds that you generally cannot recover from the seller.

Yes — in England, Wales and Northern Ireland gazumping is legal, however frustrating it feels. Until written contracts are exchanged, an accepted offer is only an agreement in principle ('subject to contract'), and the seller can walk away or take a better offer without penalty. There is no law against it, and successive proposals to ban it have never made it into legislation.

Scotland is different. There, once the seller's solicitor accepts an offer and missives (the contract letters) are concluded, the deal is legally binding — and this typically happens much earlier in the process than exchange does in England. Scottish solicitors' professional rules also generally prevent them from acting for a seller who tries to accept a rival offer after one has been accepted. Gazumping in Scotland is therefore rare, though not strictly impossible before missives are concluded.

You can't remove the risk entirely in England and Wales, but the single biggest factor is time: the shorter the gap between offer acceptance and exchange, the less opportunity there is for a rival bid. Practical steps that make a real difference:

A lock-out agreement (also called an exclusivity agreement) is a legally binding contract in which the seller agrees not to negotiate with or accept offers from anyone else for a fixed period — commonly four to eight weeks. That window is designed to give you enough time to complete your survey, searches and mortgage application and reach exchange without being outbid.

It doesn't force the seller to sell to you; it only takes the property off the table for other buyers during the exclusivity period. If the seller breaches it, you can claim back your wasted costs. Lock-out agreements are not standard practice — a solicitor needs to draft one, which adds cost, and not every seller will agree — but they're worth raising on a purchase where you'd be badly exposed, such as after paying for an expensive survey on an unusual property.

First, find out from the agent exactly what the rival offer is — not just the price, but the buyer's position. If they're in a long chain and you're not, you may be able to keep the deal by emphasising speed and certainty rather than matching the money. Sellers regularly stick with a slightly lower offer from a buyer who can definitely proceed.

If you do consider increasing your offer, set a hard ceiling based on what the property is worth to you and what your lender will support — a higher price can mean a down-valuation and a bigger deposit requirement. Sometimes the right call is to walk away and put your money towards the next purchase rather than an emotional bidding war.

You can also insure against the costs in advance. Home buyer protection insurance typically costs roughly £50 to £100, and reimburses a chunk of your conveyancing, survey and mortgage fees if the purchase falls through due to gazumping or other specified reasons. Buy it when your offer is accepted, not after things go wrong.