Should I remortgage? A decision guide with actual numbers

Well over a million UK fixed deals end during 2026. The difference between acting and not acting is usually hundreds of pounds a month — but not always. Here's how to tell which side you're on.

The 60-second version

• Fix ending within 6 months? Start now. You can lock a rate today that starts when your deal ends — and usually still switch if rates drop in between.
• Already on the SVR? You're paying the market's inertia premium — typically 2–3 percentage points over new deals. Moving is almost always worth it.
• Mid-fix with early repayment charges? Usually stay put. ERCs of 1–5% of the balance eat most savings. Do the sum before touching anything.

When remortgaging clearly pays

The gap is the whole game. Take your current (or soon-to-be) rate and the best rate you could switch to, and turn it into pounds per month:

Against that, total switching costs typically run £0–£2,000 (many remortgage deals include free legals and valuation; arrangement fees are often optional for a slightly higher rate — see remortgage fees explained). When the monthly gap is in three figures, breakeven arrives in weeks.

When it doesn't pay

• Small balance. Under ~£50,000 the same rate gap produces a small cash saving, and fixed fees loom larger. Some lenders won't take balances under £25k at all.
• Selling soon. A new fix brings new ERCs, which you'd pay on sale — though "portable" deals can move house with you.
• Your circumstances worsened. New self-employment, lower income, worse credit? A remortgage means fresh affordability checks. A product transfer with your current lender usually doesn't — that comparison here.
• ERCs still apply. Breaking a fix mid-term costs 1–5% of the balance. Occasionally worth it after big rate falls — run both sums before believing anyone who says so.

The six-month window

The single most useful mechanic in the whole process: most lenders let you secure a new deal up to six months before your current one ends. Locked rate too high in hindsight? Many lenders let you swap onto a cheaper deal any time before completion. Rates rose instead? You keep the rate you locked. That asymmetry means the rational move is to lock early and re-check before completion — waiting to see is the only strategy with no upside.

What to do this week

1. Dig out your current rate, balance, remaining term, and deal end date (annual statement or lender app).
2. Run the gap through the calculator — 30 seconds, and it tells you whether the rest of this list matters.
3. Get your lender's product-transfer offer (online, no obligation) and one whole-of-market view — fee-free brokers exist and are paid by lenders.
4. Compare including fees, lock the better one, diarise a re-check for two weeks before completion.