Gazumping and gazundering: what they are and how to protect yourself

By Chris Pollitt · Last checked 6 November 2026 · 2 min read

In England and Wales, agreeing a sale isn't legally binding. Either side can pull out, or change the price, right up until contracts are exchanged. That gap is where gazumping and gazundering happen.

Gazumping

Gazumping is when a seller accepts your offer, then accepts a higher one from someone else, or asks you to pay more to keep the deal. It's most common when the market is busy and prices are rising. It's frustrating, and you may lose money already spent on a survey, a valuation and legal fees, but it isn't illegal.

Gazundering

Gazundering is the reverse: a buyer lowers their offer at the last moment, often just before exchange, knowing the seller is committed to buying their next home and may not want to start again. It tends to happen more when the market is slowing.

Not every price change is gazundering. If a survey finds a real problem, it's reasonable for a buyer to ask for a reduction to cover it. What matters is whether there's a genuine reason.

How buyers can protect themselves

• Ask for the home to be taken off the market once your offer is accepted. Agents don't have to agree, but many will.
• Be ready to move quickly. Have your mortgage in principle, deposit and conveyancer lined up so the time to exchange is as short as possible.
• Agree a timetable with the seller at the start.
• Consider an exclusivity or lock-out agreement, where the seller agrees not to deal with anyone else for a set period. Some buyer protection insurance policies also cover your costs if the seller pulls out.
• Keep in regular, friendly contact with the agent and seller.

How sellers can protect themselves

• Check the buyer's position before accepting: their mortgage in principle, proof of deposit, and whether they need to sell first.
• Prepare your paperwork early so there are fewer delays and fewer reasons to renegotiate.
• Price realistically. If the sale price matches what similar homes have actually sold for, a buyer's valuation and survey are less likely to give them grounds to lower their offer.
• Don't feel forced to accept a last-minute reduction. Ask for the reason in writing and take advice from your agent.

Will the rules change?

There have been calls for years to make home buying more binding, such as reservation agreements and earlier exchange, and the government has consulted on reforms. For now, speed and good communication remain the best protection.