Gilt yields and fixed mortgage deals: why fixed rates change between Bank Rate decisions

Fixed mortgage deals change for reasons that have nothing to do with the Bank of England's next meeting. Lenders price fixed rates off wholesale funding costs, and the biggest single input is the yield on UK government bonds, known as gilts. When gilt yields move, fixed deals are repriced or withdrawn, often within days, even though Bank Rate has not moved. Bank Rate was held at 3.75% at the Monetary Policy Committee's last four meetings as of 17 July 2026¹.

The gap between the two is the point. Bank Rate is voted on eight times a year². Gilt yields move every trading day. UK 10-year gilt yields fell from 4.66% on 31 March 2025 to 4.51% on 30 June 2025, then rose to 4.76% on 30 September 2025³. Each of those moves feeds into the cost of funding a fixed mortgage, and lenders respond by repricing their ranges.

If you already have a fixed-rate mortgage, none of this changes your payment. Your rate stays the same until the fixed period ends⁴. What it changes is what you are offered when that period ends, and how quickly a deal you were looking at can disappear.

Fixed rates follow gilt yields, not just Bank Rate

A fixed-rate mortgage does what it says: you pay the same interest rate for an agreed number of years, before going back to the lender's standard variable rate or, if you choose, remortgaging⁷. The rate is set for an agreed period, often two or five years⁸. Borrowers most commonly take out two-year or five-year fixed-rate mortgages, although three, seven, ten and even fifteen year terms are available⁴.

The lender has to fund that promise. It borrows on wholesale markets, or uses swap arrangements, to fix its own cost for the same period. Those costs track gilt yields and swap rates, which is why a fixed deal can be repriced on a Tuesday morning when Bank Rate has not moved since the last MPC meeting.

The practical effect is that fixed rates respond to expectations about inflation, government borrowing and global demand for UK debt, not only to the Bank of England's decision. A fixed deal is therefore a bet on where wholesale funding costs go over the term, priced by the lender and offered to you as a single rate.

Once you are inside the fixed period, market moves do not reach you. HSBC states that even if interest rates change, monthly payments on a fixed-rate mortgage stay the same until the end of the fixed-rate period⁹. Barclays makes the same point: the change will not affect your payments immediately, but probably will when your fixed period ends and your mortgage moves to the variable rate shown in your mortgage documents¹⁰. Leeds Building Society puts it plainly: your interest rate will stay the same during the fixed rate period, and after that time, unless you take out another mortgage product, a variable interest rate applies for the rest of the term¹¹.

What a gilt is and why its yield moves

A gilt is a UK government bond. With a bond or gilt you lend money to a body for a fixed time period in return for a fixed rate of interest¹. Gilts usually offer lower yields than other bonds because they are so low-risk². The yield is the return you get if you buy at the current price and hold to maturity, so it moves inversely to the price: when the price falls, the yield rises. Market prices fluctuate, so your return will vary depending on the timing of your trades and market interest rates³.

Two features matter for mortgage pricing. First, gilts are traded daily, so their yields move constantly. With gilts, market prices fluctuate, and your return will vary depending on the timing of your trades and market interest rates¹². Second, some gilts are index-linked. An index-linked gilt differs from a regular gilt because its interest payments are linked to the current Retail Price Index in the UK, so the interest payment goes up or down in line with UK inflation¹³. Index-linked gilts often have a long time to run to maturity, and the buying or selling price in the meantime can go up or down¹⁴.

For a mortgage borrower, the relevant point is simpler: gilt yields are the market's view of what it costs the government to borrow, and lenders' wholesale funding costs sit close to them. When yields rise, the cost of funding a fixed mortgage rises with them, and fixed rates tend to follow. When yields fall, fixed rates tend to ease. The link is not mechanical and not instant, but it is the main reason fixed deals move between Bank Rate decisions.

Tracker or fixed: how each responds to market changes

The two product types respond to market moves in opposite ways, and the choice between them is a choice about who carries the risk.

Tracker mortgages are variable rate deals that track the Bank of England base rate plus a set percentage⁷. Barclays describes its tracker as not tying you down to a fixed rate, so your payments could go up or down¹⁵. At the end of the term, you can either switch to a new tracker or fixed rate, or the lender moves your mortgage to its follow-on rate¹⁵. Yorkshire Building Society notes that after the tracker period, the mortgage reverts to a lender's standard variable rate and you can choose to get a new deal¹⁶.

Some trackers carry a collar. This is because some tracker mortgages come with a collar, which means the rate can only fall to a set level⁷. If your mortgage deal has a collar, your interest rate will not fall any lower than the figure specified¹⁸. The rate can still rise when Bank Rate rises, so a collar caps the benefit of falling rates without capping the cost of rising ones.

A standard variable rate mortgage is the fallback for both. As the name suggests, your mortgage payments can go up or down¹⁹.

When a deal is withdrawn or repriced

Lenders withdraw and reprice deals constantly, and the pattern is not random. When wholesale funding costs rise, or when a particular deal attracts more applications than the lender has funds allocated for, the deal is pulled and reissued at a different rate. Barclays Mortgage removed products from its range in the week to 25 September 2026, and other lenders repriced in the same period²⁰.

The practical consequence is that a mortgage offer is not a standing price. If you are watching a deal, it can disappear before you apply, and the replacement may be priced differently. This is why the timing of an application matters as much as the rate on the day you look.

There is some protection for existing borrowers approaching the end of a deal. Customers approaching the end of a fixed rate deal have the chance to lock in a deal up to six months ahead⁶. Customers who are up to date with payments can switch to a new mortgage deal with their lender at the end of their existing fixed-rate agreement without a new affordability check²¹. Lloyds Bank says you can usually switch to a new deal 3 to 4 months before your existing fixed term ends²².

Fees and charges if you lock in or switch

The cost of changing a mortgage depends on when you do it, not just what you choose.

• Switching at the end of the fixed term: if you have come to the end of your fixed mortgage term there should not be any cost associated with switching providers²⁴.
• Switching before the fixed term ends: you will be charged an early repayment fee if you switch before your fixed rate ends²⁵. If you want to switch to a fixed deal during your agreed term, there may be fees for doing so²².
• Moving house mid-term: you may need to pay a product switch or additional borrowing fee²⁶. You might be able to port your rate instead of having to get a new deal if you move house during the fixed term²². You could take your fixed rate deal with you if you move home, subject to conditions²⁷.
• Overpaying: most fixed-rate mortgages allow you to overpay up to 10% of the balance each year, either in regular overpayments or on an ad-hoc basis, and overpaying more in a 12-month period may trigger an early repayment charge⁴. Fixed-rate mortgages typically allow penalty-free overpayments of up to around 10% of the outstanding balance each year⁵.

Before making any change, check your mortgage agreement to see whether you would have to pay any fees or penalty charges²⁸. The allowance and the charges vary by lender and deal, so the figure that applies to you is the one in your own documents.

Where a fixed rate leaves you worse off

A fixed rate buys certainty, and certainty has a price. If the lender's standard rate falls below your fixed rate, you will lose out¹⁷. You are locked into a rate that is now above the market, and leaving early means an early repayment charge.

The risk is asymmetric in the other direction too. While rates are falling, they remain significantly higher than in the 2010s, which means that generally fixed-rate mortgages will offer a better deal²⁹. That is a statement about the level of rates, not a recommendation, and it can change.

Borrowers with large discounts may be in a particularly vulnerable position when their deal comes to an end, as they could face a large and sudden increase in their interest rate when they are moved to the lender's SVR²⁹. The same cliff edge applies to fixed-rate borrowers who do not remortgage: at the end of the fixed period you must remortgage or be moved to the lender's SVR, which is usually much more expensive³⁰.

There is a specific mis-selling scenario to be aware of. If you were given a fixed-rate mortgage and told to remortgage to a better deal later on, and incurred penalties for leaving the fixed rate early, that is one of the situations the mis-selling guidance covers³¹.

If you are struggling with payments, lenders have a set of possible arrangements: reducing your payments for a set period, charging interest only for a while on a repayment mortgage, giving a payment holiday, or extending the mortgage term to reduce payments³². These depend on your payment history and whether your difficulties are long or short term. Free, impartial help is available from MoneyHelper and from debt advice charities such as StepChange³³.