GBP SONIA swap rates have continued their slow grind higher. The 5-year swap is now around 4.2–4.3% depending on source, up roughly a quarter of a point since late June; the 2-year sits a touch lower at around 4.1–4.2%. This week’s move was small — a few basis points at most — but the direction has been consistently upward for three weeks.
What’s notable is that buy-to-let fixed-rate pricing hasn’t followed yet. Our checks of limited-company BTL product ranges this week found no new launches, withdrawals or repricings — lenders are still offering the same 5-year fixes they were in late June, despite funding costs having risen meaningfully underneath them. Margins are being compressed rather than passed on, which tends not to last.
Our read: if swaps hold at these levels or keep rising, the next round of BTL product reissues is more likely to price up than down. For anyone holding a mortgage offer on a 5-year fix agreed before this move, the case for keeping it — rather than waiting for something cheaper to appear — looks stronger this week, not weaker. Bank of England base rate remains at 3.75%.