How much can I save by remortgaging?

It depends on the rate gap, the balance and the fees. On a £180,000 balance with 20 years left, moving from an example rate of 5.5% to 4.5% saves £99.43 a month — £2,386.28 over a 2-year fix, or £1,387.28 after £999 of fees.

When should I start looking to remortgage?

About three to six months before your current deal ends. Many lenders let you lock in a rate up to six months ahead, so you can secure a deal before you move onto the standard variable rate.

Do remortgage fees wipe out the saving?

Sometimes. A £999 fee on the example above still leaves £1,387.28 saved over two years, but a £2,500 fee would leave you £113.72 worse off. Always compare the saving over the fixed period against the total fees.

Is it worth extending the term when I remortgage?

It lowers the monthly payment but raises total interest a lot. On £180,000 at 4.5%, stretching from 20 to 30 years saves about £227 a month but adds over £55,000 of interest. Keep the remaining term if you can afford the payment.

Will I pay an early repayment charge if I switch early?

Possibly. Leaving a fixed deal before it ends can trigger a charge, often 1–5% of the balance. Check your mortgage terms before switching, and factor the charge into the saving.

Can I remortgage to release equity?

Yes — you borrow extra against your home's value and the new total becomes your mortgage balance. The payment rises, and the debt is secured on your home, so run the new balance through the repayment calculator first.

Remortgage Calculator UK

TL;DR: Switching a £180,000 balance with 20 years left from an example rate of 5.5% to 4.5% cuts the payment from £1,238.20 to £1,138.77 a month — a saving of £99.43 a month, £2,386.28 over a 2-year fixed period, or £1,387.28 after £999 of fees. All rates are yours to enter; 5.5% and 4.5% are examples only. Fees can wipe out the saving, so always compare the saving against the fees.

Current mortgage balance (£) Current interest rate (% per year) — enter your rate Years left on current mortgage New interest rate (% per year) — enter the new deal’s rate New term (years) Fees for switching (£ — arrangement, valuation, legal) Fixed period of the new deal (years)

Model: both payments are standard amortisation at the single rate you enter for each deal. Real rates change when a fixed deal ends, and extending the term lowers the payment but raises total interest. This calculator is not mortgage advice.

When does remortgaging save money?

Remortgaging means taking out a new mortgage on a home you already own, usually to replace a deal that has ended. Most fixed-rate deals last 2 or 5 years. When the fixed period ends you move onto the lender’s standard variable rate, which is usually higher — that is the moment most people switch. The saving comes from the rate gap: every percentage point off the rate on a £180,000 balance saves roughly £90–£100 a month. But the saving is only real if it beats the cost of switching. A deal with a low rate and a £1,999 fee can cost more than a slightly higher rate with no fee, especially on a smaller balance or a short fixed period. That is exactly what this calculator compares: the saving over the fixed period, minus the fees.

The worked example above shows the maths clearly. The monthly saving of £99.43 over a 2-year fix is £2,386.28 in total. After £999 of fees, the net saving is £1,387.28, and the fees pay for themselves in about 10 months. If the fees were £2,500 instead, the net saving would be negative — you would lose £113.72 over the two years. Same rate cut, opposite answer. Always run the fees through the calculator before choosing a deal.

New monthly payment by rate (£180,000 over 20 years)

New example rate	Monthly payment	Saving vs 5.5% (£1,238.20)
3.5%	£1,043.93	£194.27 a month
4.0%	£1,090.76	£147.44 a month
4.5%	£1,138.77	£99.43 a month
5.0%	£1,187.92	£50.28 a month

These are example rates, shown to illustrate the size of the saving. Your lender’s rates will differ, and they change daily.

The term trap: a lower payment that costs more

When you remortgage you can choose a new term, and lenders often suggest starting a fresh 25 or 30 years. That cuts the monthly payment — but it also restarts the clock, so you pay interest for longer and the total interest rises sharply. On a £180,000 balance at an example rate of 4.5%, a 20-year term costs £1,138.77 a month and £93,305.21 of interest in total. Stretching to 30 years drops the payment to £912.03 a month but raises total interest to £148,332.53 — over £55,000 more. If you remortgage, keep the term the same as the time you have left, unless you genuinely need the lower payment. You can also shorten the term if your income has risen, which saves interest but raises the payment.

Other reasons people remortgage

To release equity. Borrowing extra against the home’s value, for example for an extension. The extra borrowing is added to the balance, so the payment rises — run the numbers in the Mortgage Repayment Calculator with the new total.
To borrow more cheaply than a personal loan. Mortgage rates are usually lower than unsecured loan rates, but the debt is secured on your home and lasts far longer, so the total cost can be higher.
To change the deal type. Moving from a variable rate to a fixed rate for certainty, or to an offset mortgage if you hold large savings.
To consolidate debts. Rolling other debts into the mortgage lowers the monthly cost but stretches the debt over decades and puts your home at risk if you cannot pay. Think carefully and take advice before doing this.

Start looking about three to six months before your current deal ends. Many lenders let you lock in a new rate up to six months ahead, and an early repayment charge may apply if you switch before the fixed period ends — check that charge first, because it can be thousands of pounds and can wipe out the saving entirely. A mortgage broker can compare deals across lenders, including ones you cannot apply to directly, and a broker’s advice is regulated by the Financial Conduct Authority.

Product transfer vs remortgaging elsewhere

When your deal ends you have two ways to switch. A product transfer means staying with your current lender and moving to one of its new deals. It is usually faster and cheaper: there is often no valuation fee, no legal fee and no new affordability check, because the lender already knows you. The drawback is that your current lender’s deals may be worse than the wider market, and you will never know unless you compare. Remortgaging to a new lender means a full application, a valuation, legal work and possibly fees — but also access to the whole market, which can mean a better rate. Many borrowers ask their current lender for a product transfer quote and a broker for a whole-market comparison, then pick the better one. A broker is paid by commission from the lender or a fee from you, and must disclose that; a fee-free broker can be a good starting point. If you stay with your current lender, the switch is often completed in days rather than weeks, and there is less risk of something going wrong at the last minute. If you move lenders, allow six to eight weeks and start well before your current deal ends, so you are not pushed onto the standard variable rate while the paperwork is still moving.

When remortgaging is a bad idea

Remortgaging is not always the right move. If you plan to move home within the next year, a new fixed deal with an early repayment charge could cost more than it saves — a portable mortgage, which you can carry to the new home, or a short fix can avoid that trap. If your home has fallen in value, your loan-to-value may have risen, which can mean a worse rate than the one you have, or no offer at all. If your income has fallen or your credit record has worsened since you took the mortgage, a new lender may offer less, or refuse, while your current lender’s product transfer may not need a fresh affordability check. And if your balance is small — say under £50,000 — the monthly saving from a rate cut may be so small that the fees and the hassle are not worth it. In that case, overpaying the small balance (see our overpayment calculator) may be the better use of the money. The calculator above will tell you the truth in numbers: if the net saving after fees is negative or tiny, staying put is the right answer.

Sources: FCA mortgage rules (MCOB 11); GOV.UK “Mortgages” guidance. Rates are user-entered examples, not market rates. Checked 13 November 2026.

Important: Everything on this site is general information for planning purposes only. It is not professional financial advice, not tax advice, and not a substitute for advice from a qualified adviser. Rates and thresholds are for the UK tax year 2026/27 (6 April 2026 – 5 April 2027) unless stated otherwise, and can change. Figures are estimates — your actual pay depends on your tax code, pension scheme, student loan plan and other deductions. Check the current figures on GOV.UK or speak to a qualified adviser before acting.