When Should You Remortgage? UK Timing Guide 2026

The best time to start reviewing your mortgage is usually three to six months before your existing deal ends. This gives you time to compare your current lender’s product transfers with remortgage offers from other lenders, check any early repayment charge and plan when the new deal should start.

Starting a search early does not mean completing a remortgage early. You may be able to arrange an offer now but complete after your existing deal ends, avoiding an unnecessary early repayment charge. The right timing depends on your lender, offer validity and circumstances.

When to begin your mortgage review

Around six months before your current deal ends is a sensible starting point. Many lenders allow you to secure a new mortgage offer several months ahead, although the booking window and offer expiry date vary. Starting early gives time for affordability checks, valuations and conveyancing where required.

For a straightforward product transfer, your existing lender may allow you to reserve a new rate in advance. If you switch to another lender, you will normally need a new application and legal work. See our Remortgage vs Product Transfer guide for the differences.

Your remortgage timeline: six months to completion

Time before current deal ends	What to do	Why it matters
Six months	Check your end date, mortgage balance, ERC schedule and current lender’s offers. Start comparing lenders.	Some deals can be reserved well before the current rate ends.
Four to five months	Review total costs, eligibility, property value and any additional borrowing.	Gives time to identify lender criteria or documentation issues.
Three months	If switching lenders, progress the application, valuation and conveyancing.	Allow around 6 to 8 weeks as a current planning estimate based on our experience, although individual cases can take longer.
One to two months	Confirm the mortgage offer, legal progress, product fees and intended completion date.	Helps avoid an unwanted gap on the lender’s follow-on rate.
At the existing deal’s end	Complete the remortgage or start the new product transfer at the agreed time.	Avoids unnecessary early repayment charges where possible.

This is an illustrative planning schedule, not a guaranteed lender timetable. If you have less than a month remaining, seek advice promptly rather than assuming it is too late.

Can you secure a mortgage rate six months early?

Often, yes, but it depends on the lender and product. Some mortgage offers remain valid for three to six months, while existing-lender product-transfer booking windows can differ. An offer’s validity period may run from the application or offer date, so check when it expires and whether an extension is possible.

Participating lenders under the government’s Mortgage Charter committed to helping eligible residential customers secure a new deal ahead of their current deal ending. Booking windows vary by lender and can be shorter than six months, as the table below shows. For customers up to date with payments, a like-for-like switch with the existing lender may not require a fresh affordability assessment. Check whether your lender participates, whether the commitment applies to your mortgage and its exact booking window.

Securing a rate does not mean that you must immediately redeem your existing mortgage. In many cases, the new mortgage can be timed to complete when your current deal ends. Confirm the start date, fees, cancellation conditions and whether the lender allows a change to a newer product before completion.

Can you hold a backup deal while you compare?

Some borrowers reserve a product transfer with their existing lender as a backup while applying elsewhere. If you go ahead with a remortgage, cancel the product transfer before it starts so you do not end up with two arrangements. Check the cancellation cut-off and any fees with the lender.

Typical booking windows by lender

The following are published product-transfer booking windows for eligible existing mortgage customers. These are not new-lender mortgage offer validity periods.

Lender	Existing-customer product transfer booking window
Halifax	Up to 4 months before the current deal ends. The new deal can start after the existing product ends. Halifax also permits certain earlier starts within the final 3 months without an ERC.
Santander	Eligible customers can first reserve a new deal just over 4 months before the existing deal ends. Some may qualify to switch early to a lower rate without an ERC.
NatWest	Up to 4 months before the current deal ends for eligible existing customers.
Nationwide	Fixed-rate customers can switch without an ERC when less than 4 months remain. Different rules apply to tracker and follow-on rates.
HSBC	Up to 90 days in advance for an eligible product switch. An earlier exit from the existing deal may incur an ERC.
Barclays	Up to 90 days before the current rate ends in the app or Online Banking. Earlier switches may be possible in specific circumstances, with an ERC potentially payable.

Lender information checked against each lender’s published guidance: 14 October 2026. These are existing-customer rate-switch rules, not promises that every customer can reserve a deal for the full period. The rules for reserving a rate, starting it early, cancelling it and paying an ERC differ. Barclays’ 90-day booking window is confirmed in its published rate-switch guidance. Confirm your own eligibility, rate start date, early repayment charge and cancellation cut-off before applying.

Should you remortgage before your fixed rate ends?

You can consider it, but an early repayment charge may outweigh any benefit from switching. Check the amount payable on the actual date you would redeem your existing mortgage. Some lenders reduce the charge as the deal progresses, and some permit a switch within a particular window without a charge.

How to compare the cost of switching early

Suppose your existing mortgage would charge a £3,000 ERC if you left now. A competing deal appears to reduce your repayments by £100 a month. The simple comparison is £3,000 divided by £100, or 30 months of payment difference. That is not proof that switching is worthwhile or that you will save £100 every month for 30 months.

A proper calculation also includes arrangement fees, legal costs, interest over the relevant period, any change in term and the balance remaining at the end. If the alternative is only available for a shorter fixed period, a simple payback calculation may be misleading. These figures are hypothetical, not live rates or a client outcome.

Read our detailed guide to remortgaging with an early repayment charge and remortgage costs and fees.

What happens if your mortgage deal ends before you switch?

If no replacement deal starts when your introductory rate expires, your mortgage will normally move to your existing lender’s standard variable rate (SVR) or another follow-on rate specified in your offer. That rate can be higher than available new deals, but the actual difference depends on your lender and the market.

You do not lose your mortgage when a fixed rate ends. You continue making repayments under the mortgage contract, but your rate and payment may change. Check your lender’s notice, compare a product transfer and remortgage, and confirm when either option can take effect.

Is a product transfer faster than a remortgage?

A straightforward product transfer can often be arranged within days, subject to your lender’s process and booking window. Moving to a different lender typically involves underwriting, valuation and conveyancing. Based on our current experience, allow around 6 to 8 weeks for a straightforward new-lender remortgage. This is a planning estimate, not a guarantee. Underwriting, valuations, legal work or complex circumstances can extend the timescale.

A product transfer may be particularly relevant when your income has changed and you are not increasing your borrowing. Some existing lenders do not require a fresh affordability assessment for a straightforward like-for-like switch. Other changes can trigger checks. Our product transfer comparison explains the criteria.

What if mortgage rates rise or fall while you are waiting?

Do not assume you can predict the market. If rates rise, a rate you reserved earlier may be useful. If rates fall, you may be able to change to another product before completion, but not every lender permits this, and fees, new checks or deadlines may apply.

Ask your adviser to check the terms of the specific offer. A rate reservation should be part of a wider cost and eligibility comparison, not a bet on the direction of interest rates.

When might waiting be better?

Waiting may be worth considering if an ERC makes an immediate switch expensive, if your mortgage balance is about to move into a better loan-to-value band, or if you need time to gather documents. It can also be appropriate when your existing deal is competitive and a replacement would cost more overall.

However, waiting until the last moment can create a risk of moving onto a higher follow-on rate. You can often start reviewing now and complete later, rather than treating early research and early redemption as the same decision.

When should you review your mortgage if your circumstances have changed?

If your income, employment, credit history or household circumstances have changed, begin the review earlier rather than later. A new lender may require fresh affordability and credit checks, while an existing-lender product transfer may be available under a different process.

Self-employed applicants and company directors may be asked for accounts, tax calculations (sometimes called SA302s), corresponding tax year overviews and other evidence. Requirements vary by lender. See remortgaging when self-employed and remortgaging with bad credit.

If you have only recently bought your property, some lenders impose minimum ownership periods or additional checks. Read the individual lender criteria before applying.

What is the six-month rule for remortgaging?

Many lenders will not consider a remortgage until you have owned the property for at least six months. This is an industry convention rather than a law, and some lenders will consider an earlier application in specific circumstances, such as a delayed purchase or a change of borrower. The same phrase is sometimes used to describe securing a new deal up to six months before your current one ends. If you bought recently, check the lender’s minimum ownership period before applying.

What documents should you prepare?

For a new-lender remortgage, it is useful to have your existing mortgage statement, deal end date, ERC information, identification, income evidence, bank statements and details of credit commitments available. A lender may also request property or borrowing-purpose information.

The evidence for a simple product transfer may be much lighter. Do not assume that a document list or lender policy applies universally.

How Option Finance helps you plan the switch

We review your existing mortgage, identify when charges apply, compare available product transfers with suitable new-lender deals and explain the total cost and practical timing of each route. If you decide to switch lenders, we can help coordinate the application and clarify the steps needed before completion.

For the wider process, read our UK remortgage guide. You can also use our remortgage calculator to explore repayment scenarios. Calculator results are illustrations, not a mortgage offer.

Frequently asked questions

Speak to Option Finance before your deal ends

Whether your mortgage ends in six months or a few weeks, we can help you review the timing, compare the available options and understand the charges before deciding what to do.

Use the enquiry form below to request a mortgage review.

For independent guidance, see MoneyHelper’s remortgaging guide and the FCA’s mortgage affordability rules. Mortgage eligibility, fees and timelines depend on your circumstances and lender criteria.