Quick Answer: How Early to Start the Remortgage Process
Most UK lenders let you apply for a new remortgage 3-6 months before your current deal ends — without triggering an early repayment charge. The new rate is reserved at today's price, with completion timed for the day after your current deal expires. If market rates rise during the wait, you keep the locked rate. If they fall significantly, most lenders let you switch to the lower rate at no cost. Start the comparison process around 4-5 months out, get an AIP, and submit a full application 3-4 months before deal end. This avoids both the ERC trap (leaving early) and the SVR trap (delaying past expiry). Halifax, Nationwide, Santander, NatWest, HSBC, Barclays, Lloyds, and most building societies all support this 6-month pre-lock-in.
The Standard Remortgage Window: Three to Six Months
Most UK mortgage lenders allow you to apply for a new remortgage deal between three and six months before your current deal ends. This is widely known as the remortgage window, and it exists specifically to give borrowers enough time to arrange a new deal without falling onto the standard variable rate (SVR).
Here is how the typical timeline works:
- Six months before your deal ends — Some lenders and brokers will begin searching for deals at this point. A growing number of lenders now offer rate locks that last up to six months, giving you the option to secure a rate well in advance.
- Three to four months before — This is the most common point at which homeowners begin the formal application process. Most mortgage offers are valid for three to six months, so applying at this stage means your offer will still be valid when your current deal expires.
- One to two months before — If you have not yet started the process, there is still time, but you will need to move quickly. The conveyancing and legal work alone can take several weeks.
The key point is that you do not need to wait until your current deal has actually ended before you start remortgaging. In fact, waiting until the last minute is one of the most common and costly mistakes homeowners make.
Your existing lender will often write to you around three months before your deal expires, reminding you that your rate is about to change. While this letter is a useful prompt, it should not be the trigger that starts your search. Ideally, you should already be well into the comparison and application process by then.
How Rate Locks Protect You
One of the most valuable features available to remortgagers is the ability to lock in a rate months before your current deal ends. A rate lock means that the lender guarantees the interest rate they have offered you for a set period, typically three to six months. If rates go up during that time, you are protected. If rates go down, many lenders will allow you to switch to the lower rate instead.
How rate locks typically work:
- You apply for a new mortgage and receive a formal offer at a specific interest rate.
- The offer is valid for a set period — usually three to six months.
- You can set the completion date to coincide with the day your current deal expires.
- If interest rates increase before completion, your locked rate stays the same.
- Some lenders offer a rate drop guarantee, meaning if their rates fall before completion, you automatically get the lower rate.
This arrangement means there is very little downside to starting early. You secure a competitive rate with the safety net of knowing you can benefit from any further reductions. It is essentially a one-way bet in your favour.
Not all lenders offer rate locks of the same duration, so it is worth checking with your broker or lender how long the offer will remain valid. Some specialist lenders may have shorter offer validity periods, which could affect your timing.
It is also important to understand that a rate lock is not the same as a binding contract to proceed. If you receive a better offer from another lender before completion, you are generally free to withdraw and go with the alternative deal, although you should check whether any fees apply.