Yes. You can make an offer on a house before you have sold your own, and the estate agent must pass it to the seller. Whether the seller accepts is another matter: they will want to know how likely you are to get to exchange of contracts, and a buyer who still has a home to sell is usually seen as a weaker prospect than one who has already sold or has nothing to sell.
No offer is legally binding in England and Wales until contracts are exchanged, so neither you nor the seller is committed when an offer is accepted. This guide explains what agents must do with your offer, how sellers judge your position, the ways to fund a purchase before your sale completes, and the Stamp Duty cost of owning two homes at once.
Under the Estate Agents (Undesirable Practices) (No. 2) Order 1991, it is an undesirable practice for an agent to fail to forward to their client promptly and in writing accurate details of any offer received, and that includes conditional offers. The only exception is offers of a type the seller has said in writing they do not want to receive. The same order says an agent must not knowingly or recklessly misrepresent the status of a buyer, which expressly includes their financial standing and their ability to exchange contracts quickly.
Agents registered with The Property Ombudsman also follow its Code of Practice for Residential Estate Agents. It requires them to:
So expect questions about your own sale and your mortgage when you make an offer. You do not have to use any mortgage, conveyancing or other service the agent offers. The law prevents an agent from discriminating against a buyer who will not take its services, and the Ombudsman's code says this includes passing on your offer less quickly than others.
Once an offer is accepted subject to contract, the seller decides whether the property comes off the market or carries on being marketed. If marketing continues, the Ombudsman's code says the agent must tell you in writing and make clear in its marketing that an offer has been accepted. By law the agent must still pass on any further offers until exchange.
A seller is not obliged to accept the highest offer. They are weighing price against the risk that the sale falls through or drags on, and your own sale is a big part of that risk.
First-time buyers, people renting and cash buyers with funds in place are not waiting for anyone else, so their offers are usually the most straightforward for a seller to accept.
You have a buyer and the conveyancing has started, so you are in a chain, but the seller can see your sale is moving. This is generally the strongest position for someone who has a home to sell.
The seller has no way of knowing how long your sale will take or what price you will achieve. Some sellers will accept, often on the basis that they keep marketing until you find a buyer. Others will ask you to come back once you have sold.
This is the weakest position. Unless you can fund the purchase without selling, most sellers and agents will treat the offer as a sign of interest rather than a firm proposal. If you have found the right house, the quickest way to strengthen your offer is to get your own home valued and on the market.
Written offers are made subject to contract, and a spoken offer is never legally binding. Both sides can still change their minds, and the price can still be renegotiated, for example after a survey. The agreement only becomes legally binding when contracts are exchanged. From then on, a buyer who pulls out is likely to lose their deposit, which is often 10% of the price.
GOV.UK puts the average time to buy or sell a home at about 5 months, and longer in a chain. Our guide to how long solicitors take to process a house sale explains where the time goes, and our article on property chains and how they can be broken covers what happens when one link fails.
Your budget depends on the equity in your current home: its likely sale price, less your outstanding mortgage, any early repayment charges and your selling costs. Ask your lender how much you owe, whether early repayment charges apply and whether there are fees to move your mortgage. An up-to-date valuation of your current home gives you a realistic figure to work from.
A mortgage in principle, also called an agreement or decision in principle, is a lender's written estimate of how much it might lend you. It is not a mortgage offer, it typically lasts 30 to 90 days and it is usually free, though some brokers charge. Some lenders run a soft credit check, which does not show on your credit file, and others a hard check, which does. You do not legally need one to make an offer, but having one shows the seller you have started arranging finance. Your mortgage in principle plus your deposit or equity is your buying budget.
If you have a mortgage, you will need to move it to your new home or pay it off. Moving it, known as porting, lets you take your current deal and rate with you. The ported rate only covers what you already owe, and any extra borrowing will be on a separate rate. Ask your lender how porting works for you and what happens if your sale and purchase do not complete on the same day. Our independent mortgage advice page lists two independent brokers we recommend, who can compare porting with a new mortgage.
A bridging loan is short-term borrowing used as a temporary solution while you move to longer-term finance, for example until your old home sells. Citizens Advice warns that the interest will be high, so work out the full cost before you commit, including fees and what happens if your sale takes longer than expected. A bridging loan secured on a home will usually be a regulated mortgage contract, which means it falls under the Financial Conduct Authority's mortgage rules, although some business and other bridging loans fall outside regulation. Check that any lender or broker is on the FCA register.
Some owners keep their current home and rent it out, often called let-to-buy. You must tell your lender if you plan to let a property with a residential mortgage. Some lenders will give consent to let on your current deal, while others will want you to switch to a buy-to-let mortgage. If your lender will not agree, remortgaging with another lender may be an option, though early repayment charges may apply.
Think carefully before choosing this to get a purchase moving. You will own two homes, so the higher rates of Stamp Duty will normally apply to your purchase, and you can only reclaim them if you sell the old home within 3 years. From 1 May 2026, new private tenancies in England are periodic with no fixed end date, section 21 "no fault" evictions have ended, and a landlord cannot evict tenants in order to sell within the first 12 months of a tenancy. To end a tenancy so that you can sell, you must also give at least 4 months' notice. Capital Gains Tax may also be due when you eventually sell a home you have moved out of; our guide to the property 36-month rule explains how the relief works.
Some housebuilders offer part exchange, where the developer buys your current home as part of the deal for one of its new homes. The two purchases are made in exchange for each other, so you are not waiting for a buyer of your own. The developer decides what it will pay for your home, so compare its figure with an independent valuation before agreeing. You can browse current developments through our new homes search.
Stamp Duty Land Tax (SDLT) applies in England and Northern Ireland. Scotland and Wales have their own taxes with different rules.
If at the end of the day you complete your purchase you still own your previous main home, and you will own more than one residential property worth £40,000 or more, you will usually pay the higher rates. These are 5% on top of the standard rates. The rules apply to you and your spouse or civil partner together, and to anyone buying with you. If your sale completes before your purchase, or on the same day, and the new property will be your main home, the higher rates do not apply on that basis.
The extra cost is significant. HM Land Registry's UK House Price Index puts the average price in Cambridge at £475,151 in July 2026. At that price, SDLT at the standard rates would be about £13,760 and at the higher rates about £37,520, so owning your old home on completion day would add about £23,760.
You can claim this back. If you sell or give away your previous main home within 3 years of buying your new one, you can apply to HMRC for a refund of the higher-rate part. You must claim within 12 months of the later of the sale of your old home or the filing date of the SDLT return for your new one. You cannot get a refund if you or your spouse still own any part of the old home. If you bought on or after 1 January 2017, HMRC may still allow a refund outside the 3 years where exceptional circumstances, such as government restrictions or action by a public authority, prevented the sale. Even with a refund, you need the cash to pay the higher rates when you buy.
This article is general information, not financial, tax or legal advice. Speak to a mortgage adviser, tax adviser or solicitor about your own circumstances.
They can, but they do not have to. Many sellers prefer buyers who have sold subject to contract or have nothing to sell. If your home is on the market, the seller may accept and keep marketing until you find a buyer.
Yes. An agent must forward every offer, including conditional ones, to the seller promptly and in writing, unless the seller has said in writing that they do not want offers of that type.
Expect to be asked. Agents following The Property Ombudsman's code must take reasonable steps to find out where your money is coming from, including whether you need to sell, and tell the seller.
No. In England and Wales an offer is not legally binding until contracts are exchanged, so either side can still withdraw or renegotiate before then.
Usually, yes. If you still own your previous main home when you complete, the higher rates (5% on top of the standard rates) normally apply. You can claim a refund if you sell your old main home within 3 years of buying the new one.
