Bank of England base rate: 3.75% Avg 2-year fix: 5.09% Avg 5-year fix: 5.12% Today’s ratesGuides
Remortgaging

Remortgaging explained: timing, costs and traps

Roughly a fifth of UK mortgage holders are sitting on a standard variable rate at any given time, mostly because a fixed deal ended and nobody did anything. At 7.03% average SVR against 5.12% for a new five-year fix, that inaction costs around £234 a month on a £200,000 balance. This guide is about not being in that group.

When to start

Six months before your current deal ends. Not three, not one.

Most lenders issue mortgage offers valid for three to six months, and the rate is held for that whole period. So you can secure a rate half a year out, and if the market improves before completion, most lenders will let you switch down to their cheaper product. You get the upside of a fall and protection from a rise. There is no equivalent argument for waiting.

The other reason to start early is that a full remortgage takes four to eight weeks from application to completion, and chains of small delays are normal. Leaving it to the final month means real risk of landing on the standard variable rate for a month or two while paperwork completes, which is exactly the outcome you are trying to avoid.

Product transfer vs full remortgage

These are two genuinely different things and the distinction matters more than most people realise.

Product transfer compared with a full remortgage
Product transferFull remortgage
What it isNew deal with your current lenderMoving to a different lender
Affordability checkUsually noneFull assessment
Credit searchUsually soft or noneHard search
Legal workNoneRequired, often free with the deal
ValuationNone or automatedRequired
TimeDaysFour to eight weeks
RateOnly what your lender offersThe whole market
Can you borrow more?Sometimes, with checksYes, subject to affordability

The sensible sequence is to get your existing lender's product transfer quote first, which takes minutes in the app, and then check whether the open market beats it by enough to justify a full application. Often it does by a meaningful margin. Sometimes it does not, and the transfer is simply the better answer.

A product transfer is also the safer route if your circumstances have deteriorated: recently self-employed, on probation, income reduced, or new credit problems. Because it typically skips the affordability assessment, it can be available when a full remortgage would be declined.

What it costs

Working out whether it is worth it

The comparison people usually make is between the two rates. That is the wrong comparison. What matters is the total cost over the length of the new deal, including every fee, which is what the remortgage calculator does.

A worked example. You have £185,000 outstanding, 21 years remaining, currently on a 7.03% standard variable rate. A new five-year fix at 5.12% with a £999 fee:

That is an obvious yes. The decision gets genuinely difficult when you are mid-fix with an early repayment charge, or when the balance is small enough that a £999 fee eats the rate saving. Below roughly £50,000 outstanding, look specifically for fee-free products even at a higher headline rate.

Using your LTV as leverage

Two things have been quietly working in your favour since you took the mortgage: you have repaid capital, and the property has probably gained value. Together those can move you into a cheaper pricing tier.

The tiers are hard steps, not a smooth curve. 80.1% LTV is priced as 85%. So if you are close to a boundary, a targeted lump sum before you apply can pay for itself several times over in the rate.

Worth checking before you apply. On a £200,000 balance, moving from the 85% tier to the 80% tier saves roughly £27 a month, about £1,600 over a five-year fix. If you need £4,000 of overpayment to get there, that is not obviously worth it. If you need £900, it clearly is. Work out your exact position on the remortgage calculator and model the lump sum on the overpayment calculator.

Borrowing more at the same time

Remortgaging is the usual way to fund an extension, a loft conversion or a new kitchen, because secured borrowing at around 5% is far cheaper than an unsecured loan at 8 to 12%.

Two cautions. First, spreading £30,000 of kitchen over 21 years at 5.12% costs about £19,000 in interest, so the cheap monthly rate hides an expensive total. Consider a shorter term on the additional borrowing if your lender allows it. Second, additional borrowing triggers a full affordability assessment even with your existing lender, so it is not a formality.

When remortgaging is difficult

The one habit that matters. Put a calendar reminder six months before your deal ends, right now, on whatever device you actually check. Everything else in this guide is optimisation; that reminder is the thing that prevents the expensive mistake.

Mortgages Calculators UK editorial team

Rate data verified 28 August 2026 from Rightmove and Moneyfacts market averages. This guide is information, not financial advice or a recommendation of any lender or product.

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