If your fixed rate has an end date, that date is not a soft deadline. Six months out is when the groundwork starts, not when you casually start browsing best-buy tables. The gap between "sorted a new deal in good time" and "rolled onto the SVR by accident" is entirely down to whether you did anything in this window — and the SVR gap can run to several percentage points, which on a typical mortgage balance is not a rounding error.

This is a sequenced checklist, not a list of options to consider whenever. Work through it in order starting six months before your current deal ends.

1. Confirm exactly when your fix ends — and mark it

Do this: 6 months out Risk of missing: SVR default

Check your original mortgage offer document for the precise end date, not just "some time next year". Lenders vary in when they start writing to you about it — some as little as a few weeks before expiry — and if you've moved house, changed your email, or simply don't open lender post promptly, that notice can be missed entirely.

Miss the end date and you move onto the lender's standard variable rate automatically, on the day your fix expires, with no grace period. So if you only do one thing this month, find the exact date and put a reminder in six months out from today.

2. Work out your current loan-to-value (LTV)

LTV bands: 90% / 85% / 75% / 60% Crossing a band can cut your rate materially

Your LTV is your outstanding mortgage balance divided by your property's current value — and it's likely improved since you took out your current fix, through a combination of scheduled capital repayment, any overpayments you've made, and general house price growth over the term. Mortgage pricing moves in bands, so crossing from, say, 85% down to 75% LTV can move you into a noticeably cheaper rate tier, not just a marginally better one.

Get a realistic current valuation — a free online estimate from a major portal is a reasonable starting point, though your new lender will do their own valuation regardless. If you're close to a band boundary, even a modest overpayment before you apply could be worth the cost, because the rate difference between bands compounds over the whole term of the new deal.

3. Get your credit file in order

Do this: 5–6 months out Avoid new credit applications pre-application

Pull your credit file from one of the major reference agencies and check for errors — a missed payment recorded incorrectly, an old account that should have closed, or someone else's data cross-matched to your address are all more common than people expect. Dispute anything wrong now, because corrections can take weeks to process and you don't want that clock running during your actual mortgage application.

Avoid taking out new credit — a new phone contract, a car finance deal, even a new credit card — in the months before you apply, since each hard search and new commitment can affect both your score and your affordability calculation just when a lender is scrutinising it most closely.

4. Decide: porting vs. remortgaging

Porting: keep your rate, same lender Remortgaging: switch lender for a better deal

Porting means taking your existing mortgage deal with you to a new property (if you're moving) or extending it with the same lender — this can make sense if your current rate is genuinely competitive and you want to avoid early repayment charges. Remortgaging means moving your mortgage to a new deal, potentially with a different lender entirely, and is the more common route if you're staying put and simply want to fix again at the best available rate.

If your current rate is well below where the market has moved, porting to protect it can be worth the extra paperwork; if the market has moved in your favour or your existing lender's follow-on rates aren't competitive, remortgaging with a whole-of-market search is usually the stronger move. Either way, decide this before you start approaching lenders, not partway through.

5. Broker vs. going direct to your existing lender

Whole-of-market broker: often free (lender-paid commission) Fee-charging brokers: typically £300–£500

A whole-of-market broker searches deals across the entire lending market rather than the handful your existing lender offers you as a "product transfer", and many operate on a commission basis paid by the lender — meaning there's no direct cost to you for using one. Some brokers charge a flat fee instead, typically in the low hundreds, usually in exchange for access to a wider panel or more complex case handling.

Going direct to your existing lender is faster and involves less underwriting, but you're only ever seeing that one lender's rates, which may not be the best available to you given your improved LTV or credit position. If your situation is straightforward, comparing your lender's product transfer rate against a broker's whole-of-market search costs you nothing but time — and that comparison alone is often where the real saving sits.

6. Lock a rate early — most lenders let you

Typical window: 3–6 months ahead Booking fee risk: check if refundable

Many lenders allow you to secure a new fixed rate three to six months before your current deal actually ends, and if rates fall further before your completion date, most also let you switch to a better rate that becomes available in that window at no extra cost. This gives you a form of downside protection — you're not stuck at today's rate if the market improves, but you're also not exposed if rates rise instead.

Check whether the deal involves a booking or product fee, and whether it's refundable if you don't proceed — most are, but not universally, so read the small print before locking anything in. Locking early costs you little and protects you from the scenario where rates jump just as your fix is ending.

Worked example: 2-year vs 5-year fix on £200,000

As of July 2026, Moneyfacts best-buy tables show representative rates around 4.57% for a 2-year fix and 4.48% for a 5-year fix at typical LTV bands (Moneyfacts, July 2026 — rates move regularly, so treat these as illustrative rather than a live quote). On a representative £200,000 repayment mortgage over a 25-year term, the difference between those two rates works out to a monthly repayment difference of roughly £10–£12, with the 5-year fix coming in lower in this particular snapshot — though the more important variable is usually which rate is available at your actual LTV band once your new valuation comes back.

Your own numbers will differ based on your balance, remaining term and LTV, so run your own numbers with our mortgage calculator once you have a firm rate quote, rather than relying on this representative example. The point isn't the exact figure — it's that the 2-year vs 5-year decision is close enough on rate alone that your view on where rates are heading, and your appetite for re-doing this whole process again in two years, should probably decide it rather than the monthly payment gap alone.

If you're weighing that decision specifically, our guide to remortgage timing runs the break-even maths in more depth, and if Stamp Duty applies to a related house move rather than a straight remortgage, our Stamp Duty explainer covers the current thresholds.

Most people miss this

The biggest mistake on this entire list is doing nothing and letting the fix lapse onto the lender's standard variable rate. SVRs typically sit several percentage points above the best available fixed rates, and lenders are not obliged to chase you before the switch happens — it's automatic. If you take away one action from this page, it's this: put the date in your diary today, six months before it ends, and start step one before you forget.