A moving home mortgage is simply the loan you take out when you sell one property and buy another. The difference from your first purchase is that you already have a mortgage, so before anything else we have to decide what happens to it. You can take it with you (porting), take a new deal from the same bank, or pay it off and start again with a new lender. Your deposit usually comes from the equity in the house you are selling, and the bank looks at your income all over again at the new price.
I have been arranging mortgages for 15 years and the bit that trips people up is rarely the rate. It is timing: an early repayment charge you did not know about, a buyer who pulls out, or a valuation that comes in low. Sort those three out early and the rest is normally straightforward.
Every home move ends up on one of three routes. Which one wins depends on how long is left on your fixed rate, how much you need to borrow and whether your bank still likes your income.
Take your existing rate and balance with you. Handy if you are mid fix with a big ERC to leave, but it is still a fresh application.
Your current lender may offer a fresh product for the whole loan, or keep the old rate and add a second part for the extra borrowing.
Pay off the old mortgage when you sell and take the best deal from across the market. Often wins when your fix is ending anyway.
We price each route side by side, charges and fees included, so you can see the real cost over the deal rather than just the headline rate.
Side by side
Here is how the three routes usually compare. Every bank has its own rules, so treat this as the starting point for a conversation, not the answer.
Our porting and ERCs guide covers refund windows, blended rates and what happens if you need to borrow less.
Timing
Most moves complete on the same day, which is why moving house feels like a relay race: your buyer's money arrives, your old mortgage is paid off and your new one pays the seller. Getting there takes a few months, and each step leans on the one before.
Before you list
Dig out your mortgage offer and check the end date of your fixed rate and the ERC for leaving early. If you are not sure what your current mortgage allows, we can check it for you. Get a decision in principle so you know your budget.
Sale agreed
Instruct a conveyancer straight away. Then make an offer on your next place with your figures ready.
Full application
We submit the case, the bank values the property and checks your payslips and bank statements. An offer letter usually follows within two to four weeks.
Searches and survey
Your conveyancer runs searches and raises enquiries. Book your own survey too, as the bank's valuation is for the bank.
Exchange of contracts
Everyone in the chain exchanges on the same day and the completion date is fixed. From here, pulling out costs real money.
Completion day
Funds move down the chain, your existing mortgage is cleared and you get the keys, usually by early afternoon.
If your fix ends in the next six months or so, it can pay to time completion just after it. Some banks also refund the ERC if you complete your purchase within a set window. Santander, for example, says you will not pay its ERC if you sell and buy on the same day and borrow the same or more (check the current terms before you rely on it).
Property chains
A chain is every buyer and seller whose move depends on someone else's. The longer it is, the more chances there are for a delay. For most buyers it is the most stressful part of buying a house when you already own one.
Have your paperwork ready before you list, use a conveyancer who answers the phone and get your mortgage offer early. I also keep an eye on your offer's expiry date, because if completion slips past it you need an extension.
Until exchange anyone can walk away, and you can lose money already spent on surveys and legal work. If your buyer goes, the purchase usually stalls too. Your mortgage offer normally survives, so we can carry on once a new buyer is found.
Being chain free is a real selling point. Some people sell first and rent for a few months so they can move fast. It costs more, but you become the buyer every seller wants.
Buying first
Sometimes the right house turns up before you have a buyer. You can still buy, but you need another way to fund the deposit, and every option costs more than a straight swap.
A short term loan secured on your property, repaid when your house sells. Interest is charged monthly and is far higher than a normal mortgage. Only sensible when you have a clear exit, such as a sale already agreed.
Remortgage your current home to a buy to let and release equity for the deposit, then let it out. You become a landlord, with tax and rules to match. See our let to buy mortgages page.
If your income is strong enough, a bank may lend on the new home while you still own the old one. It has to count both payments, which rules out most people, and you may pay the higher rates of stamp duty up front, then claim a refund if you sell the old home within three years.
Bridging and second charge loans are secured on your home. If the sale takes longer or sells for less than you expect, the cost can climb quickly. Your home may be repossessed if you do not keep up repayments on your mortgage.
Your deposit
Equity is what your home is worth minus what you owe. When you sell, that money pays off the old loan and the rest usually becomes the deposit on the next place.
Start with a realistic sale price, not the asking price. Take off the mortgage balance, any ERC, the estate agent's fee and legal costs. What is left is the money you can actually use.
Stamp duty, legal fees, a survey and removals come out of the same pot. On a £475,000 home that can be £18,000 or more. Our stamp duty calculator shows your figure.
Your mortgage as a share of the property price is the loan to value. Rates usually get cheaper each time you drop into a lower band, such as 90%, 85%, 75% or 60%, so a slightly bigger deposit can be worth a lot. Our loan to value calculator works it out.
Affordability
Whichever route you take, the bank will look at your finances afresh. Having a mortgage for years does not mean you will pass again on a bigger loan.
Many banks cap lending at around 4.5 times household income, with some going to 5 times or more for higher earners or certain professions. Two incomes are added together.
Car finance, credit cards, childcare and school fees all reduce what you could borrow. Banks also test if you could still pay if interest rates went up, and a poor credit score can rule some of them out. Paying off a small loan before you apply can make a difference.
New job, going part time, a baby on the way or a switch to self employment all change the picture. Tell us early. Our self employed mortgages page covers how banks read accounts.
Our mortgage borrowing calculator gives a quick guide, and the check further down this page puts your equity and income together. The borrowing and deposit guide goes through the detail.
The application
Most people have not applied for a mortgage in five or ten years, and the process has moved on. Here is what happens once you have an offer accepted on your new home.
We run a soft search with a credit reference agency and get a decision in principle online, usually the same day. It gives you a clear idea of what you could borrow before you start house hunting, and it does not mark your credit rating.
Once the purchase price is agreed, we send the full mortgage application with payslips, bank statements and ID. The bank checks your credit score, your financial commitments and any other loans, then books a valuation of the new property.
A fixed rate keeps monthly payments the same. Tracker rates follow the Bank of England base rate. Most home movers take a repayment mortgage, though an interest only mortgage is possible for some borrowers with a clear repayment plan.
Your conveyancer asks the seller's conveyancer for the property questionnaire, title and energy performance certificate (EPC). It is worth reading the EPC early, as a poor rating can mean higher bills and some banks offer better deals on efficient homes.
A lower rate with a big product fee can cost more overall than a slightly higher rate with no fee. We compare the overall cost of each mortgage deal over the fixed period, including any ERC on your current mortgage.
Once you have exchanged contracts the mortgage offer is used to fund completion. If house prices or the property value move after that, it does not change the loan. Get your home insurance sorted before then.
Bigger or smaller
Upsizing is the most common move I see: a growing family, more space to work from home or a better school catchment. You will nearly always borrow more. If you port, the extra usually sits on a separate product with its own rate and end date, and it is worth checking that the two parts line up for next time.
Buying somewhere smaller can mean a smaller loan or no mortgage at all. Watch the ERC: if you port but borrow less, many banks apply it to the part you pay back. Older borrowers may also find the term is shorter, as banks look at your age at the end of the mortgage term.
Worked example
Figures are for illustration only, based on the kind of case we see every week. Your own numbers will be different.
Sarah and Tom own a three bed semi in Romsey that should sell for £350,000. They owe £160,000 on a five year fix with 18 months left and a 2% early repayment charge. They want a £475,000 four bed and earn £72,000 between them.
£350,000 sale, less the £160,000 mortgage and about £4,200 in agent's fees, leaves roughly £185,800. Buying costs come next: £13,750 stamp duty at standard home mover rates in England, around £2,500 for legal fees and searches, £600 for a survey and £1,200 for removals. That leaves about £167,750 for the deposit.
£475,000 less £167,750 means a mortgage of about £307,250, which is roughly 65% loan to value. At 4.5 times income they could borrow up to about £324,000, so the numbers work if the bank's affordability check agrees.
Port and add
Keep the £160,000 on the old rate and borrow about £147,250 more on a new product. No ERC if both sides complete on the same completion date.
Switch lenders
Pay the £3,200 ERC (2% of £160,000) and put the full £307,250 on the best rate available. Worth it only if the saving on monthly repayments over the deal beats that cost.
Wait for the fix to end
Time completion for 18 months' time and the ERC disappears, if they can find a buyer and seller willing to wait.
The lesson: the cheapest headline rate is not always the cheapest move. We put all three side by side, fees and charges included, before you choose.
Calculator
Put in your own numbers to see how much equity you could take forward, how big a mortgage you would need and if your income looks likely to stretch to it. For the full cost of the move, use our moving home calculator.
Costs
The mortgage is only one part of the bill. These are the costs people forget to budget for.
Stamp duty
Home movers pay standard rates. In England a £475,000 purchase is £13,750. Scotland and Wales have their own taxes.
Legal fees
You pay conveyancing fees on both the sale and the purchase, plus searches and Land Registry fees.
Estate agent
Often around 1% to 1.5% of the sale price, plus VAT, paid when you complete.
Bank fees
Product fees, valuation fees and any ERC on your existing mortgage.
Survey and removals
A survey on the new home, removal firms and sometimes a short overlap on bills.
Our fee
Fee free on over 90% of cases. £299 under £100,000, and up to £995 for complex or adverse cases.
See the costs and mortgage types guide for a full breakdown and how to choose between a fixed rate and a tracker.
Protecting the move
Most banks want buildings insurance in place from exchange, because that is when the new property becomes your risk. Move your home insurance and contents cover over for moving day too. Our buildings and contents insurance page explains the options.
A bigger mortgage usually needs bigger cover. We are mortgage and protection advisers, so we look at life insurance and income protection alongside the loan. The legal, insurance and planning guide has a full checklist.
Some of the lenders we compare when you move
This page gives you the overview. Each of these goes deeper into one part of the move.
How much you could borrow at the new price, how your equity becomes the deposit and what loan to value means for your rate.
How porting really works, when early repayment charges apply, refund windows and what happens if you need to borrow more.
Stamp duty, legal fees, surveys and removals, plus fixed, tracker and other mortgage types for your next deal.
Conveyancing, exchange and completion, buildings insurance and protection, and a timeline for planning the move.
Add up the full cost of your move in one place: stamp duty, legal fees, estate agent, survey and removals.
The question I get asked most by home movers is what happens to the mortgage they already have. Here is the short version.
Most mortgages are portable, which means you can port your mortgage to the new property and keep your current interest rate for the rest of the fixed term. You still have to pass the lender's checks again, including a fresh affordability assessment and a valuation on the new home, so porting is never automatic.
If you are still inside a fixed rate, paying off your current mortgage to take a new mortgage elsewhere usually triggers early repayment charges, often 1% to 5% of the balance. Porting avoids them in most cases. If your sale and purchase do not complete on the same day, some lenders take the charge first and refund it once the new mortgage completes.
If you need more than your current mortgage balance, the extra is lent as a separate mortgage product at today's mortgage rates. You end up with two parts, each with its own interest rate and end date. That works fine, but try to line the end dates up so one part does not sit on a high variable rate.
Staying with the same lender is not always cheapest. We compare the cost of porting plus any extra borrowing against a new mortgage deal with a different lender after paying the early repayment charge. Our porting and early repayment charge guide shows how we work it out.
Before your home goes on the market, use our mortgage calculators to see how much you could borrow and what your monthly payments might look like at current interest rates. Then give us a call and we will check it properly against real lenders.
Thinking about moving? Talk to us before you accept an offer on your home.
Call 03300 432 428We are fee free on over 90% of cases. Where a fee does apply, it is £299 on mortgages under £100,000 or up to £995 on more complex or adverse cases, and we always tell you before any work starts.
Your home may be repossessed if you do not keep up repayments on your mortgage.
.webp)
More questions
Allow two to four weeks from application to offer, and around three to four months from sale agreed to completion. Chains, searches and surveys are usually what slow it down, not the bank.
Yes. Get one before you put your house on the market, or at least before you make an offer. Agents take you more seriously and it flags any credit problems early.
It is hard but not always impossible. Some banks let you port and take the shortfall with you, but that is rare. Most people in negative equity wait, overpay or stay put.
Yes. A port is assessed like a new loan. If your income has dropped or your outgoings have gone up, you may not be able to port, even with a perfect payment record.
Your offer normally stays valid for around six months, so a new buyer can often be found in time. If it looks like running out, we ask for an extension or rebook the case.
Most of our clients pay nothing. We are fee free on over 90% of cases. Mortgages under £100,000 carry a £299 fee, and complex or adverse cases can be up to £995. We always tell you before you commit.
Your home may be repossessed if you do not keep up repayments on your mortgage. Alexander Southwell Mortgage Services Ltd is authorised and regulated by the Financial Conduct Authority (FCA no. 1011890).
