Remortgaging explained: the complete UK guide

If you own a home with a mortgage on it, remortgaging is the biggest lever you have over what that home costs you each month. Around 1.8 million fixed deals in the UK end during 2026, and each one is a decision: switch lender, switch deal with the lender you already have, or do nothing and let the rate revert. This guide covers all three, what each really costs once the fees are counted properly, and how the rules changed in 2025. It is written for homeowners, not first-time buyers. If you are still buying, start with our first-time buyer guide instead.

What remortgaging actually is

Remortgaging means taking out a new mortgage with a different lender and using it to pay off the one you have. The house does not move and no money changes hands with a seller. What changes is who you owe and on what terms. Legally it is a new loan secured on the same property, which is why it comes with an application, checks and a solicitor even though nothing about your life has changed.

Three different things get called remortgaging, and they behave very differently.

A product transfer is a new deal with the lender you already have. Same loan, same balance, same term, new rate. Your lender is repricing a loan it already owns rather than underwriting a new one, so it is usually a form and a few days.

A further advance is extra borrowing from your current lender on the same property, priced as its own deal alongside your main one. Two balances, two rates, one house.

Doing nothing is also a choice, and it has a price. When a fixed, discounted or tracker deal ends, your lender moves you onto its standard variable rate automatically. Nobody rings you. The payment changes.

No SDLT, LBTT or LTT on remortgaging your own home: replacing a mortgage without changing ownership creates no chargeable consideration. A transfer of equity is different. Source: HMRC, Revenue Scotland, WRA · Verified August 2026.

Why most refinancing never leaves the lender

Here is a number almost no remortgage guide leads with. For 2026, UK Finance forecasts £77 billion of external remortgaging and £261 billion of product transfers. By our arithmetic on those two forecasts, just over three quarters of UK refinancing by value never leaves the existing lender.

That is not because three quarters of borrowers are lazy. It is because a product transfer is often the better answer, and it is worth understanding why before you assume switching is the goal.

A product transfer skips almost everything expensive. No valuation, usually no legal work, and in most cases no fresh affordability assessment, because your lender is not lending you anything new. If your circumstances have got worse since you borrowed, that matters enormously: your existing lender is repricing a debt it already owns, whereas a new lender is deciding whether to take you on from scratch.

Switching pays when the gap is real. The transfer rate your lender offers is not always competitive, and the further your loan-to-value has improved since you borrowed, the more likely a new lender beats it. If your home has gone up in value or you have paid the balance down, you may have crossed into a better LTV band that your current lender is quietly not passing on.

So the honest question is not “should I remortgage” but “is the gap between my lender's offer and the open market big enough to be worth the cost and the checks”. Most guides skip that, because most guides are paid when you switch. This one is not.

What happens if you do nothing

When your deal ends you revert to your lender's standard variable rate. The SVR is set by the lender, not by the Bank of England, and it can change at any time for any reason. It usually sits well above what the same lender offers a new customer, which is the uncomfortable part: your reward for staying quietly on the books is the worst rate the lender sells.

Nothing about this is a penalty and nothing is hidden. It is simply the default, and defaults are where money goes to die. As of June 2026 the average revert-to rate is around 6.60% while the most competitive fixes at 75% LTV sit near 4.65% to 4.81%. On a large balance over a long remaining term, that gap is not a rounding error.

The SVR does have one genuine advantage: it almost never carries an early repayment charge. If you are about to sell, or about to pay off a lump sum, a few months on it buys flexibility you would otherwise pay an ERC for. That is a deliberate short-term trade, not a plan.

What actually decides whether switching pays

Almost every remortgage comparison online compares monthly payments. Old payment, new payment, difference times twelve, headline saving. It is clean, intuitive, and frequently wrong.

Three things break it.

Fees added to the loan do not disappear, they compound. Roll a product fee into the balance and you have not avoided paying it. You have borrowed it, at your mortgage rate, for as long as the loan runs. Take the first example below. Pay the £1,299 of fees upfront and you are £27,858 ahead over five years. Add the same £1,299 to the loan and you are £27,590 ahead: £268 worse off for not writing a cheque. Small on a £200,000 loan, and it scales with the fee and the term. But note the direction. A payments comparison would tell you adding the fee was cheaper.

A longer term always lowers the payment. Stretching a mortgage from 18 years back out to 25 cuts what you pay each month whatever the rate does. That is arithmetic, not a saving.

The early repayment charge is a real cost on day one. Break a fix early and it is typically a percentage of the outstanding balance. It does not appear in a payment comparison at all.

Put those together and you get a common, entirely avoidable outcome: your payment falls by £100 a month, you feel better, and five years later you owe thousands more than if you had done nothing.

The only comparison that survives all three is net position: what you have paid out plus what you still owe, at the same point in the future, on each path. That is what our Remortgage Savings Calculator computes. It does not tell you your payment went down. It tells you whether, once everything is counted, you are actually ahead.

Here is the test we hold our own engine to. Switch to an identical rate, for an identical term, on an identical balance, and pay £1,249 in fees. The answer has to come back at exactly minus £1,249, not a penny either side, because nothing has happened except the fees. If a comparison cannot pass that test, it is not comparing what you think it is.

Three worked examples, each a verified test case from the calculator's own regression matrix rather than a snapshot of today's market. Figures rounded to whole pounds.

Two caveats. The maths assumes the SVR stays put, because modelling a future rate path means guessing, and a calculator that guesses lies with more decimal places. And it models switching now, not later: if your fix has a while to run, re-run it nearer the end.

The costs, and how to compare deals properly

Costs vary widely by lender and loan size, so this table points at the document carrying your actual figure, not a range that will not match it.

Three of these deserve more than a table row.

The product fee is a rate in disguise. Lenders sell the same money two ways: a lower rate with a high fee, or a higher rate with no fee. Which wins depends on your balance and how long the deal runs. A £999 fee on a £500,000 loan is noise. The same fee on an £80,000 loan is a meaningful chunk of the saving. There is no general answer, which is exactly why it needs calculating rather than reasoning about.

Early repayment charges are usually tiered. A five year fix might charge 5% in year one falling to 1% in year five, on the balance outstanding when you redeem. Your annual statement or your original offer spells out the ladder. Find it, because it is often the number that decides the whole question.

Your ESIS answers most of this. The European Standardised Information Sheet, sometimes still called a Key Facts Illustration, is the standardised summary every regulated lender must give you. It states the rate, what happens when the deal ends, every fee, and the ERC ladder. When two deals look confusingly similar, comparing the two ESIS documents beats comparing two websites.

How lenders decide what you can get

Three separate things decide the offer you see, and they are easy to blur together.

Regulatory rules set the floor: the FCA requires a lender to check a mortgage is affordable, with carve-outs covered in the next section.

Lender policy sits on top, and it is where most rejections actually happen. Maximum income multiples, maximum LTV, acceptable income types, acceptable property construction. None of that is regulation. It is each lender's own appetite, it varies enormously between lenders, and it changes without notice. That is the real argument for a whole-of-market broker: not secret rates, but knowing whose policy currently fits your shape.

Credit assessment is the individual decision at the end.

Two levers matter more than the rest, and both have their own guide and calculator here. Your loan-to-value band is the one rate improvement you can engineer yourself, by paying a little off or waiting for a valuation to catch up with what your home is worth. Affordability is tested on what you earn now, not on what you earned when you first borrowed; our affordability calculator and how much can I borrow guide cover what lenders actually test.

Your existing lender, on a product transfer, usually asks for none of it.

The rules: what changed, and what is changing next

This section is dated deliberately. Everything else in this guide is written to age well. This part will not.

What changed in July 2025. The FCA published Policy Statement PS25/11 on 22 July 2025, the first output of its Mortgage Rule Review, effective the same day. Three changes matter if you are remortgaging.

The big one: the modified affordability assessment was widened. It already let a lender skip the full affordability test for borrowers stuck on expensive legacy deals, but only with the lender they already had. PS25/11 extended it to a new lender, where the new mortgage is more affordable than either your current one or anything your current lender is offering you. In plain English, the rule that stopped some people escaping a bad deal was loosened.

Alongside it, the full affordability check was removed for term reductions, so shortening your mortgage to pay it off faster no longer triggers a complete assessment. And the advice trigger was removed, so talking to your lender about your options no longer automatically turns the conversation into regulated advice.

The catch, which almost nobody spells out: all three are permissive, not mandatory. The FCA told lenders they may do these things. It did not tell them they must. Lenders still owe you a duty to lend responsibly and still apply their own policy. So “the rules changed but my lender still said no” is not a contradiction. It is the design.

What is changing next. The FCA published CP26/18, Mortgage Rule Review: supporting first-time buyers and underserved consumers, on 9 June 2026, aimed at people the market currently serves badly: variable and irregular incomes, the self-employed, later-life borrowers, interest-only borrowers, and people with historic credit problems. The consultation ran until 28 July 2026 and the FCA expects final rules in the second half of 2026. Separately, the loan-to-income flow limit behind the “4.5 times income” ceiling is under review. If your last application was declined on income evidence or on an interest-only repayment strategy, this is the space to watch. And note the pattern holding: these proposals are permissive too.

The Mortgage Charter

Alongside the FCA rulebook sits the Mortgage Charter, and it is worth being precise about what it is. Not law, not an FCA rule: a set of voluntary commitments brokered by the government in June 2023 and made by lenders themselves. Forty-seven lenders have signed it, covering around 90% of the UK mortgage market, and they publicly recommitted in March 2026.

Two of those commitments matter directly if your deal is ending.

You can lock in a new deal up to six months ahead, and then ask your lender for a better like-for-like deal right up until the new one actually starts, if one has appeared meanwhile. Read that twice. It is the best asymmetric bet in this guide: downside protection from securing a rate early, and you keep the upside if pricing improves. It costs nothing and it is almost certainly the most under-used commitment on this page.

If you are up to date with your payments, you can move to a new deal with your existing lender at the end of your fix without another affordability assessment.

The Charter carries further commitments for people struggling, covered below. But hold on to what it is: an industry promise, not a right. If your lender has not signed it, none of it applies, and checking takes a minute.

How it works, step by step

Start about six months out. This is not folk wisdom. It is a commitment your lender has probably already made: under the Mortgage Charter, signatory lenders let you lock in a new deal up to six months before your current one ends, and let you ask for a better like-for-like deal right up until the new one starts. MoneyHelper's own guidance says the same, that six months or less to run is the point to start looking. So starting early is close to free, and it removes the single worst outcome, which is landing on the SVR by accident because the paperwork ran late.

Find out what you are actually on. Your rate, your deal end date, your balance, your remaining term, your ERC ladder. All of it is on your annual statement or in your lender's app, and nothing sensible happens before you have those five numbers.

Get your lender's transfer offer first. Free, minutes, and the benchmark every other option must beat. Then compare properly: not the payment, the net position, with fees and any ERC included. Once you have a rate you like, the repayment calculator shows what the monthly payment becomes.

If you are switching lender, expect four to eight weeks, and have your ID, payslips or two to three years of accounts, and bank statements ready. A product transfer usually needs none of it.

Broker, or direct? A product transfer needs nobody: paying for advice to press a button your lender will let you press for free is a poor trade. Switching lender is where a broker earns their fee, not because they have rates you cannot see, but because they know whose policy fits your situation. Ask how they are paid and whether they are whole of market, then check them on the FCA's Financial Services Register. It takes a minute, and it is the only way to know the person advising you on the largest debt of your life is authorised to do it.

Then diarise the next one. The end date of the deal you have just taken is the start of the next decision. Six month warning in the calendar. That habit is worth more than any rate hunting.

Special situations

Your income has changed. Self-employment, a career break, parental leave or contract work all make a new lender's affordability test harder, while your existing lender's product transfer usually stays open. Secure that transfer offer before you go exploring. CP26/18 proposes changes here, but proposals are not rules.

You are on interest-only. A new lender wants a credible repayment strategy for the capital, and what counts varies. Your existing lender is far likelier to reprice an interest-only loan it already holds than a new one is to take it on.

You have a Help to Buy equity loan. You need the scheme administrator's permission, and remortgaging usually requires a formal valuation, because the equity loan is a percentage of your home's value rather than a fixed sum. Start with the GOV.UK guidance in Sources, and start early: the permission step is not fast.

You are letting the property out, or you have moved abroad. A residential mortgage on a property you no longer live in needs either consent to let or a move to a buy-to-let product. Non-resident and visa-holding borrowers face a much smaller lender panel and generally need a broker who works in that space specifically; our guide for foreign nationals covers the ground.

You are adding or removing someone from the mortgage. That is a transfer of equity as well as a remortgage, and the tax treatment turns on a detail almost nobody flags: whether the other person takes on part of the existing debt, or pays for their share. Either is chargeable consideration and stamp tax may follow. Get it checked before you commit.

You are stuck with a lender that no longer sells mortgages. This is the “mortgage prisoner” situation. The FCA's modified affordability assessment exists for exactly this and, since July 2025, can be used by a new lender. It is not a guarantee: no lender is obliged to use it. MoneyHelper has the clearest impartial explainer, linked in Sources.

You are struggling to pay. Remortgaging is not the tool for this, and a guide is not the help you need. Two things, in order.

First, contact your lender, ideally before you miss a payment. They have a regulatory duty to work with you, and under the Mortgage Charter, asking your lender about your options does not affect your credit score at all. Signatory lenders can offer a term extension or a temporary switch to interest-only payments, both without an affordability check.

Second, get free independent help. MoneyHelper's help with mortgage payments is the government-backed place to start, and Citizens Advice covers your rights if things have already gone further. Neither charges you a penny, and both are better placed to help than we are.

Frequently asked questions

The bottom line

The most valuable thing you can do about your mortgage is know the date your deal ends and start looking six months before it. After that, the whole decision reduces to one comparison, done honestly: what your current lender will offer you for free, against what the open market will offer once fees, any early repayment charge, and any change to your term are all counted. Sometimes that comparison says switch. Just over three quarters of the time, by value, it does not, and there is no shame in that. Run your own numbers through the calculator, get your lender's transfer offer as your benchmark, and if the answer is close or your circumstances are unusual, speak to a whole-of-market broker before you commit.