IPSA has published the salary ranges for 2025-2026 and they can be found here:

London area: https://www.ipsaonline.org.uk/guidance/pay-and-benefits#mps-staff-pay-ranges-2025-26-london-area

Non-London area: https://www.ipsaonline.org.uk/guidance/pay-and-benefits#mps-staff-pay-ranges-2025-26-non-london-area