Why You Should Remortgage 6 Months Before Your Deal Ends

The Six-Month Rule Explained

The six-month rule is not a formal regulation but rather a widely accepted best-practice window for starting the remortgage process. Most UK mortgage lenders will allow you to apply for and secure a new mortgage offer up to six months before your existing deal expires. The offer is held for you, and the new mortgage only begins when your current deal ends.

This approach works because it eliminates the risk of ending up on your lender's SVR. The SVR is the default rate your lender moves you to once your introductory deal finishes, and it is almost always significantly more expensive. In early 2026, SVRs across UK lenders range from around 6% to over 8%, compared to the best fixed rates which are considerably lower.

By acting six months early, you also give yourself a buffer against delays. Valuations, legal work, and lender processing times can all cause holdups, and having extra time means you are not rushing to meet a deadline.

How Rate Locks Protect You

When you secure a mortgage offer six months in advance, you benefit from what is known as a rate lock. This means the interest rate you have been offered is guaranteed for the duration of the offer period, regardless of what happens to rates in the wider market. If the Bank of England raises the base rate during those six months, your locked-in rate remains unchanged.

Even better, many lenders now operate a policy where they will allow you to switch to a lower rate if one becomes available before your new deal starts. This effectively gives you the best of both worlds — protection against rate rises, with the option to benefit from rate falls. Ask your broker or lender whether this policy applies to your offer.

Without a rate lock, you would be exposed to market movements right up until completion. Given how quickly mortgage rates can change — sometimes by several tenths of a percentage point in a single week — the security of a rate lock is extremely valuable.

The Real Cost of Falling Onto the SVR

To understand why acting early matters, consider the cost of the SVR. If your lender's SVR is 7.5% and you have a mortgage balance of 200,000 pounds, your monthly interest-only cost would be around 1,250 pounds. If you could remortgage to a rate of 4.5%, that same monthly cost drops to approximately 750 pounds — a saving of 500 pounds per month or 6,000 pounds per year.

Even falling onto the SVR for just one or two months while you arrange a remortgage can cost you hundreds of pounds unnecessarily. By starting the process six months early, you virtually eliminate this risk. The money saved by avoiding the SVR far outweighs the small effort required to begin the remortgage process ahead of time.

Remember that your lender has no obligation to offer you a competitive rate when your deal ends. They will send you a letter informing you that your deal is ending and what the SVR will be, but they are under no requirement to proactively offer you a better alternative. The onus is on you to take action.

Step-by-Step: What to Do Six Months Out

Six months before your deal ends, take the following steps. First, dig out your current mortgage paperwork and note your deal end date, outstanding balance, and any ERC details. Then check your credit report for errors and take steps to improve your score if needed — paying down credit card balances and ensuring you are registered on the electoral roll can both help.

Next, contact a mortgage broker or start comparing deals online. A broker can search the entire market and recommend the best options for your specific situation, often at no cost to you as they are paid by the lender. Once you have identified a suitable deal, submit your application promptly.

Finally, keep your financial situation stable during this period. Avoid taking on new debt, changing jobs, or making large unusual transactions in your bank account, as all of these can complicate your application. The smoother your financial picture, the faster and easier the process will be.