IPSA has published the salary ranges for 2024-2025 and they can be found here: https://www.ipsaonline.org.uk/guidance/pay-and-benefits

London area: https://www.ipsaonline.org.uk/guidance/pay-and-benefits#mps-staff-pay-ranges-2024-25-london-area

Non-London area: https://www.ipsaonline.org.uk/guidance/pay-and-benefits#mps-staff-pay-ranges-2024-25-non-london-area