HighIV Macro Policy & Sovereign Debt1 October 2026, Thursday
UK long-term borrowing costs break through the 6% threshold
The yield on the UK 30-year government bond rose intraday to 6.029% on 1 October, its highest since January 1998. The 10-year yield hit 5.51%, a peak not seen since July 2007, and banks began raising mortgage rates the same day.
According to Serrari Group, the sell-off was driven by energy-led inflation risk, expectations of a tighter Bank of England (BoE), heavy bond supply and fiscal uncertainty ahead of the 28 October budget. UK inflation was 3.1% in August. The BoE held rates at 3.75% on 17 September, but 3 of its 9 members voted for a hike to 4%. According to Gokhshtein's round-up, the FTSE 100 fell 1.7% the same morning, and the 30-year yield slipped back below 6% in the afternoon. The peak came just 2 weeks after the BoE fully halted its sales of long-dated bonds on 17 September. According to MPA Mag, the 30-year yield had fallen by as much as 12 basis points that day.
The sell-off fed straight through to mortgages. According to Mortgage Solutions, Barclays raised its 2-year, 75% loan-to-value remortgage product from 5.34% to 5.55% on 1 October. TSB raised rates by up to 0.3 points on some products, and Halifax announced increases of 0.10–0.15 points effective 2 October. Trading Economics data show the 10-year yield eased to 5.38% and the 30-year yield to 5.91% on 2 October.
Talay assessment
Bottom line
The break above 6% shows that demand at the far end of the curve remains weak, even though the BoE halted sales of extended-maturity bonds on 17 September. The cost passed through to mortgages within days. The most likely path is that yields stay elevated in a 5.9–6.0% band until the 28 October budget.
Likely effects
- MortgagesNegativeWeeks
The increases by Barclays, TSB and Halifax on 1–2 October raise households' remortgaging costs by 0.10–0.30 points.
- UK budgetNegative1–6 months
Extended-maturity borrowing costs nearing 6% narrow the fiscal space in the 28 October budget and increase pressure for tax rises or spending cuts.
- Global bond marketNegativeWeeks
The gilt sell-off came on the same day as sales of US and European extended-maturity bonds. Through this channel, external borrowing costs for emerging economies including Türkiye remain under pressure.
Possibilities, ranked
- 1Elevated band until the budget55%
The 30-year yield stays between 5.9% and 6.0%, and banks keep raising product rates in stages.
Watch: The daily close of the 30-year gilt yield and the 28 October budget
- 2New peak30%
If energy prices rise or the budget fails to reassure, the 30-year yield closes above 6%.
Watch: The 30-year yield closing above 6% on two consecutive days
- 3Relief at the far end15%
If oil prices fall and the budget's issuance programme reduces extended maturities, yields drop below 5.7%.
Watch: The issuance split the DMO will publish alongside the budget
Probabilities are calibrated judgement based on the sources, not measurement, and are revised as new information arrives. Not investment advice.
Market reaction
Indicators affected
- 30-year gilt (intraday)▼ 6.029%
- 10-year gilt (intraday)▼ 5.51%
- Barclays 2-year fixed▼ 5.55%
- BoE policy rate▲ 3.75%
Sources
- Serrari Group — UK 30-Year Gilt Yield Breaks 6% for First Time Since 1998
- Mortgage Solutions — Lenders reprice while gilt market reaches levels not seen for decades
- Gokhshtein — UK 30-Year Gilt Yields Hit 6% for First Time Since 1998
- Trading Economics — UK 10-Year Gilt Yield
- MPA Mag — What the Bank of England's bond-sale shake-up means for mortgage rates next