Gazumping and gazundering: how to protect yourself when buying or selling in Birmingham
By Omar Novak · Updated 2026-08-19
Gazumping and gazundering both come down to the same underlying fact: in England, a sale is not legally binding until contracts are exchanged. Up to that point, either side can change their mind, and that flexibility occasionally gets used in ways that feel deeply unfair to the other party.
What each term actually means
Gazumping happens when a seller accepts a higher offer from a new buyer after already verbally agreeing a sale with someone else. Gazundering is the reverse: a buyer lowers their offer shortly before exchange, often when the seller has little practical choice but to accept because they are relying on the sale to fund their own onward purchase.
| Scenario | Who does it | Why it happens |
|---|---|---|
| Gazumping | Seller | A higher offer arrives before exchange |
| Gazundering | Buyer | Buyer senses the seller is under pressure to complete, or a survey reveals issues |
Why it is legal
Contract law in England treats an accepted offer as provisional until formal exchange, which protects buyers too: it is exactly why you are able to renegotiate or walk away if a survey uncovers a serious problem. The same flexibility that protects you can, less pleasantly, be used against you.
Other parts of the UK handle this differently. In Scotland, for example, offers become binding earlier in the process through a different legal system, which is one reason gazumping and gazundering are talked about far more in England than elsewhere. If you are relocating from a different part of the UK and are used to a different system, this earlier-stage uncertainty can come as a surprise.
The role of your estate agent
A good agent will not eliminate the risk of gazumping or gazundering, but they can reduce it. Ask how they verify a buyer’s position before accepting an offer, and whether they continue to take viewings after accepting an offer, sometimes called keeping a property “under offer” rather than fully withdrawn, since this affects how tempted a seller might be to consider a later, higher offer. Transparency about this from the outset, on both sides, tends to reduce the chance of an unpleasant surprise.
Reducing your risk as a buyer
Moving quickly once your offer is accepted genuinely helps. Have a solicitor ready to instruct immediately, respond to requests without delay, and keep your estate agent and the seller updated on your progress. Sellers are less likely to consider a higher offer from someone new if you are visibly moving fast and communicating well. Some buyers also ask about a lock-in or exclusivity agreement, though these are uncommon for ordinary residential sales and carry their own cost and complexity.
Reducing your risk as a seller
Sellers can reduce the temptation for gazundering by choosing buyers carefully in the first place: a chain-free, mortgage-ready buyer who is not relying on selling their own home first has less room to pressure you into gazundering, since you have less to lose by testing the market again. Keeping your own paperwork and searches moving quickly also shortens the window in which either scenario can happen.
If it happens to you
Take a breath before reacting. Weigh up how much time and money restarting the process would cost against accepting the changed terms. There is rarely a universally right answer, since it depends heavily on your own chain position and how urgently you need to move.
If you are gazumped, it is worth asking your agent whether the seller would consider matching the new offer before you walk away entirely; sometimes the original buyer simply was not given the chance to. If you are gazundered as a seller, check whether the reduced offer still works for your own onward purchase before rejecting it outright, since restarting a sale from scratch also has a real cost in time and, often, in your negotiating position on your next purchase.
This is general information about how the process works, not advice on your specific transaction; a solicitor can advise on your legal position if you are affected by either situation.
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Common questions
- Is gazumping illegal in England?
- No. Until contracts are exchanged, either side can walk away or renegotiate, which is why gazumping and gazundering are both legally possible, even though they feel unfair.
- How can I stop a seller gazumping me?
- You cannot fully prevent it, but moving quickly on searches and paperwork, staying in regular contact, and building a good relationship with the seller all reduce the window in which it can happen.
- What can I do if a buyer tries to gazunder me right before exchange?
- You can hold firm on the original price, walk away and remarket the property, or accept a reduced offer to avoid restarting the process. Which makes sense depends on how close you are to your own onward purchase and how the market looks.
- Do lock-in agreements actually stop gazumping?
- A lock-in or exclusivity agreement can add a financial or legal deterrent for a set period, but it is not as binding as exchange of contracts and is not commonly used in ordinary residential sales.