Gilt Yields Explained: How UK Government Bond Yields Affect Your Mortgage and Savings Rates

Forget the spreadsheet. Three numbers tell you almost everything you need:

• The slope (long minus short). Today, 30Y minus 2Y is approximately +120bp (5.40% − 4.20%). Still steep. Markets expect the BoE to hold next week but are still pricing a chunky inflation-risk premium into long-dated debt because of the Iran war and the July energy price cap rise.
• The 10-year level. Today: 4.90% (BoE IADB, 10 June). Above 4.5% means fixed-rate mortgages stay sticky. Below 5.0% means the panic phase has passed — but the structural premium hasn't.
• The 2-year level. Today: approximately 4.20%. Anchors 2-year fixed mortgages and 2-year fixed cash ISAs. Down 21bp from the May peak. Watch this one if your fix expires in 2026 or early 2027.

That's it. Slope tells you the market's regime view. The 10-year tells you about your annuity and long savings. The 2-year tells you about your remortgage.

A flat curve (long minus short below 50bp) means markets see Bank Rate near a terminal level. A steep curve (above 100bp, where we are now) means markets are paying for inflation insurance — and that insurance premium passes through to every fixed-rate product on the high street.

The Bank of England publishes the official daily curve at bankofengland.co.uk/statistics/yield-curves. Our /gilts hub shows the latest 10-year yield and the full BoE yield history at every build.

Two numbers land on this page because they define the whole calendar since May. The first: 5.10%, the 10-year gilt yield on 14 May, nine days after the Iran-driven panic peaked near 5.13% — a 28-year high for long-term borrowing costs. The second: 2.8%, the April CPI print released at 7am on 20 May.

Markets had been positioned for 3.5% or above. The 2.8% print — down from 3.3% in March — was a genuine surprise. Core CPI fell from 3.1% to 2.5%. Services inflation dropped from 4.5% to 3.2%. The energy price cap, which had been expected to push headline inflation higher, actually fell from £1,973 to £1,641 in April — a £332 annual saving for the average dual-fuel household. The Ofgem assessment period (November 2025 to February 2026) captured wholesale energy prices before the Iran conflict began.

The 10-year gilt fell 32 basis points in the ten days after the print. Mortgage lenders, who had been holding fire, cut rates again: Nationwide trimmed 15bp on selected fixes, Halifax followed with 10bp, and Santander repriced its 5-year range. By the end of May, HSBC's market-leading 5-year remortgage fix had edged down to 4.59%.

Then the reversal began. Brent crude stayed above $100 through early June. The ECB raised rates on 11 June, explicitly citing the Iran-driven inflation impulse. The 10-year gilt climbed from 4.78% on 29 May back to 4.90% by 10 June. The UK economy contracted 0.1% in April, with the ONS directly attributing the fall to Iran war effects — cancelled sporting events in the Middle East, disrupted manufacturing, and travel sector losses.

The result is a stalemate: inflation is falling, growth is contracting, and the ECB is hiking anyway. The BoE MPC meets on 18 June with that contradiction staring it down. Markets are pricing roughly a 30% chance of a hold, a 60% chance of a hold-with-hawkish-language, and a 10% chance of a shock hike.

The curve below is the snapshot every UK lender, annuity provider and pension scheme actuary is looking at this week. The 5-year point is the one most retail readers should focus on — it anchors both the 5-year fixed mortgage you remortgage onto and the 5-year fixed ISA you might be considering as an alternative.

The curve has compressed roughly 30bp at the 10-year point and an estimated 20-25bp at the short end since the mid-May peak, but remains structurally steep. The 30-year minus 2-year spread at approximately 120bp is wider than at any point between 2014 and 2022.

The 10-year has closed between 4.78% and 4.91% on every day since 26 May. That range is tight — the CPI surprise created a floor around 4.75% that held through the late-May rally, and the Iran/ECB concerns have built a ceiling around 4.95% that nobody has broken through yet. The 18 June MPC decision is the obvious catalyst to break the range in either direction.

The February-to-June arc tells the story in one chart: a calm 4.43% before the war, a spike to 5.13% on panic, a CPI-driven retreat to 4.78%, and a partial recovery to 4.90% as markets accept that the Iran inflation impulse is real even if near-term CPI looks benign.

The spread between Bank Rate and the 10-year gilt sits at 115 basis points — down from the 135bp peak in May but still more than double the 50-70bp range that prevailed before the war. That spread is the price tag on every fixed-rate product in the UK. Watch the gap, not the Bank Rate.

A gilt is a bond issued by HM Treasury. Buy one and you are lending the UK government cash in exchange for a fixed coupon and the return of your capital at maturity. The Debt Management Office issues them, the secondary market trades them daily, and the price moves with supply, demand and inflation expectations.

The yield is the return you actually earn at today's price, not the headline coupon rate. A gilt issued in 2020 with a 0.5% coupon now trades around 80p in the pound — and yields roughly 4.5% to maturity because of the capital uplift back to 100p. The DMO website shows the full schedule of gilts in issue with current prices and yields.

The inverse-price-yield rule trips people every time: bond prices and yields move in opposite directions. When yields rise, prices fall. The 30-year jump from 4.5% in autumn 2025 to 5.40% in June 2026 has knocked roughly 15% off the capital value of the longest gilts. Pension scheme balance sheets and gilt fund investors have felt that move — but a buyer at today's prices locks in the higher yield for the rest of the bond's life.

This matters in two practical ways. First, your existing gilt fund has fallen in price even though it now generates higher income — the headline NAV move is misleading. Second, a new buyer at today's prices is buying a much better deal than the headline coupon implies. For higher-rate taxpayers, low-coupon gilts trading below par convert most of the return into tax-free capital gain — HMRC exempts gilts from CGT. Our gilts buyers' guide walks through the platform mechanics.

The mechanism most mortgage borrowers do not know: when a UK lender writes you a 5-year fix, it does not fund the loan from deposits at Bank Rate. It hedges its interest-rate exposure in the swap market, paying fixed and receiving floating SONIA. The 5-year swap rate that determines its hedging cost is itself anchored to the 5-year gilt yield, plus a small spread.

That is why fixed mortgage rates do not move in lockstep with Bank Rate. Bank Rate drives variable-rate and tracker products. Gilt yields drive fixes.

The May-June lender repricing cycle is a case study in how this works. After the early-May gilt panic, lenders held fire — waiting. When the 20 May CPI print came in soft and the 10-year gilt dropped to 4.78%, the swap-rate transmission kicked in with the usual 2-3 week lag. Nationwide, Halifax, Santander, and HSBC all trimmed fixed rates through early June. HSBC's 5-year remortgage fix now sits at 4.59% — still priced inside the swap-rate window that followed the CPI print.

The risk: that window closes if the 18 June MPC outcome is hawkish. The ECB rate hike on 11 June — the first among G7 central banks since the Iran conflict — has already put upward pressure on UK swap rates. If the BoE signals a hike at the June meeting, every cut since late May reverses within two weeks. If it holds and the language is dovish, the 4.59% HSBC rate probably becomes 4.49% or lower.

The back-of-envelope rule of thumb: every 25bp move in the 2-year gilt flows into a 20-25bp move in the 2-year mortgage fix, with a 2-4 week lag. On a £250,000 25-year repayment mortgage, 25bp is roughly £32/month or £384/year. The 20 May → 10 June swing of roughly 10bp lower on the 2-year has already passed through to the high street.

For a worked example of why the 2-year point matters disproportionately, see our gilt-vs-mortgage breakdown.

The savings-side relationship is messier than the mortgage one. Bank Rate sets the cost of overnight funding for deposit-takers, so it dominates easy-access savings. As Bank Rate fell from 5.25% to 3.75% over 2025, the average easy-access rate fell from around 3.0% to around 2.4% — a near-textbook pass-through.

For fixed-term products — fixed-rate bonds, fixed-term cash ISAs — the comparator is the gilt of equivalent maturity. A bank offering a 2-year fixed bond is competing for your deposit against a 2-year gilt. If the gilt yield rises, the bank must lift the bond rate or watch retail money walk.

Here's the contradiction that should make every easy-access saver act immediately. Bank Rate has been flat at 3.75% for six months. Easy-access rates have stabilised around 2.4-2.5%. But the 2-year gilt, after the Iran-driven repricing, anchors the best 2-year fixed products around 4.40-4.55%. The spread between locking in and leaving money on deposit is roughly 200 basis points. On £50,000, that's £1,000/year you leave on the table by not acting.

The post-CPI gilt retreat from 5.10% to 4.90% on the 10-year has narrowed the premium modestly, but the structural gap remains wide. Higher-rate taxpayers outside the £20,000 ISA shelter get an extra edge: direct gilts held to maturity deliver most of their return as CGT-exempt capital gain. The CGT exemption on gilt capital gains is the structural edge most retail savers under-use. See our fixed-rate savings deep-dive for the providers worth your time.

Three concrete worked examples for the people who actually have to make a decision this month.

Profile 1 — Sarah, 52, higher-rate taxpayer with £20,000 to lock away

The best 2-year fixed cash ISA pays around 4.50% AER tax-free → roughly £1,842 over 2 years. A 2-year low-coupon gilt yielding ~4.2% looks worse on the headline. But consider the structure: a low-coupon gilt trading below par converts roughly 80% of the total return into tax-free capital gain. For a 40% taxpayer, the after-tax return on a direct gilt outside the ISA can match the ISA rate — and beats a fixed-rate bond that would lose 40% of the interest to tax.

The decision rule: if Sarah has £20,000 of ISA allowance unused, use the ISA. If she has already maxed her ISA, use direct gilts via her platform before reaching for a fixed-rate bond outside the wrapper. The savings hub lays out the after-tax comparison.

Profile 2 — Tom, 38, remortgaging in October 2026

Tom's £280,000 mortgage rolls off a 1.79% fix in October. Today's best 5-year fix at 4.59% would cost him roughly £400/month more. The 5-year gilt is approximately 4.50%; the 18 June MPC decision is the single biggest swing factor for his October rate.

Decision rule: track the 5-year gilt weekly. A move below 4.3% on a sustained basis after the MPC flags lender repricing within 3 weeks. If Tom can lock a rate up to 6 months ahead (most lenders offer this), he should book when the 5-year gilt drops below 4.3% — and break the booking only if rates fall a further 25bp. The risk of waiting past June: if the BoE follows the ECB and hikes, a 4.59% fix looks cheap in hindsight. Our mortgages hub tracks the gilt-to-mortgage transmission month by month.

Profile 3 — Priya, 61, considering an annuity vs drawdown for a £350,000 SIPP

A 65-year-old male annuitant can now lock in roughly £7,500 per £100,000 annually — still near a multi-year high. The 30-year gilt at approximately 5.40% drives this. Three years ago at the equivalent age, the same £100,000 bought roughly £5,400/year. The gilt move has delivered a 39% uplift in guaranteed retirement income.

Priya's call: the 30-year has come down from the 5.70% May peak. Each 10bp fall trims roughly £50/year from a £100,000 annuity quote. If the curve continues compressing post-CPI, the annuity window narrows. Consider locking part of the SIPP now (say £150,000 → ~£11,250/year for life) and keeping £200,000 in drawdown. The full annuity-vs-drawdown trade-off lives on our pensions hub.

The ONS publishes May 2026 CPI at 7am on 17 June — the day before the MPC decision. This is the most market-relevant UK data point of the summer. The April print at 2.8% caught everyone off guard. A second consecutive downside surprise would reshape MPC expectations entirely.

Here's what the May number needs to show. April's 2.8% came with an asterisk: the Ofgem price cap had fallen by £332 for the assessment period that ended before the Iran conflict. May will capture the first weeks of $100+ oil feeding into pump prices and supply chains. Petrol averaged 156.8p per litre in April — the highest since November 2022 — and has likely stayed elevated through May. If CPI comes in at 2.9% or below, the gilt rally extends and the 10-year breaks below 4.75%. Below 4.75%, fixed mortgage rates get another round of cuts. If CPI prints 3.2% or above, the ECB rate hike suddenly looks like a blueprint, and the 10-year retests 5.0% within hours.

The 17 June release is the single data point that decides whether the MPC on 18 June is a non-event or a policy pivot. Calendar it.

The other summer pivots: the BoE August Monetary Policy Report (the quarterly forecast that sets the MPC's framework), the 1 July Ofgem price cap announcement for Q3 2026 (likely to rise significantly — the assessment period captures the full Iran oil shock), and the August labour market release. Each can move the curve 10-20bp on the day.

Practical rule: if you have a remortgage or savings lock decision pending, the week of 17-24 June is your information window. Wait for both the CPI print and the MPC decision, watch the 2-year reaction, then act. Pre-decision panic is almost always more expensive than waiting five trading days for clarity.

The curve will move; here is what each move means in practice. Two signals are now in play; two remain distant.

Signal 1 — 2Y gilt breaks below 4.0%. Trigger to lock a 2-year fixed mortgage. Below 4.0%, the swap-rate transmission means lenders should release sub-4.2% 2-year fixes within 3-4 weeks. Currently 20bp away — the 2-year sits at approximately 4.20%, the closest it's been since early May. A soft 17 June CPI print combined with a dovish MPC could trigger this within weeks.

Signal 2 — 10Y gilt sustains above 5.0%. Trigger to lock long savings, fixed annuities, or buy index-linked gilts. Above 5.0%, the long-end risk premium is at levels that historically only persist when inflation expectations have shifted structurally. A hawkish MPC on 18 June — or an ECB-style rate hike — puts this signal back in play within days. Currently inactive: the 10-year at 4.90% is below the threshold after the CPI-driven retreat.

Signal 3 — Curve flattens to under 50bp (30Y minus 2Y). Trigger: fixed mortgage rates stop falling and the savings-account-vs-gilt arbitrage closes. Currently at approximately 120bp — wide open. A flattening would mean markets have priced out the long-end inflation premium, which would be the strongest signal yet that the BoE is winning the inflation fight. The Ofgem July price cap announcement on 1 July is the next test.

Signal 4 — Curve inverts (2Y above 10Y). Classic recession warning. The UK economy just contracted 0.1% in April. If the BoE hikes into a contracting economy, watch for the 2-year to push above the 10-year. Currently the 2Y is approximately 70bp below the 10Y — distant, but the ingredients are forming.

One signal that doesn't wait: the 5-year point. Every 10bp move on the 5-year gilt flows into HSBC, Nationwide, Halifax and Santander's headline 5-year fixed mortgage rates within 2-4 weeks. If you read one number, read this one. We update the live curve on the /gilts hub at every build.

This article is for informational purposes only and does not constitute financial advice. You should seek independent financial advice before making any investment decisions. Gilt prices and yields change daily; check live data and your provider's published rates before transacting.