Three lenders pulled their fixed rates yesterday. Swap rates (the wholesale cost lenders pay to fund mortgages) are above 4%. Your monthly payment just got more expensive. If you're mid-application or thinking about buy-to-let refurbishment finance, you may wish to review your numbers now with your broker.

The average mortgage rate has surged 59 basis points (hundredths of a percentage point) since late February, climbing from 4.89% to 5.48% (Moneyfacts, 24 March 2026). Two-year fixed rates now stand at 5.51%, whilst five-year fixes sit at 4.95% (Moneyfacts, 24 March 2026). On a typical £250,000 buy-to-let property, that 59-basis-point jump adds roughly £123 per month to your interest cost.

What makes this sharp? The spike mirrors the "mini-Budget shock" of September 2022 in both scale and speed. Deal availability has contracted sharply - lenders pulled 1,500 mortgage products since the conflict began, a 21% shrinkage in residential options (Moneyfacts, 24 March 2026). First-time buyers felt it hardest: 204 deals at 95% LTV vanished between 6 March and 24 March (Moneyfacts, 24 March 2026).

Saturday alone saw 52 products disappear (Moneyfacts, 24 March 2026) - the same number that disappeared in one day back in September 2022.

Why is this happening?

Swap rates remain elevated above 4%, forcing lenders to reprice daily. Rachel Springall from Moneyfacts noted that "swap rates continue to sit above 4%, so it is likely more lenders will need to reassess their ranges if margin adjustments have been insufficient" (Moneyfacts, 24 March 2026). Lenders either tighten their criteria, raise rates, or pull products entirely. You're seeing all three happen at once.

The average rate now sits at its highest level since August 2024.

What happens next?

If swap rates stay elevated, expect more daily repricing. For buy-to-let investors, that means:

Your stress test just got harder. Lenders use a stress rate - typically 2-3% above the product rate - to calculate affordability. Your application is now assessed against 7.5-8.5% instead of 7.0-8.0%. Rental income must cover it.

Lender criteria will tighten. Some will require higher deposit percentages. Others will cut loan amounts. You may find 85% LTV products disappearing next, forcing a bigger deposit upfront.

Rate locks matter now. If you're offered a rate, you may wish to consider requesting the longest reservation period available. In this environment, the trend is upward.