According to the Chartered Institute of Editors and Proofreaders these are the suggested minimum rates from 1 March 2024:

Type of workSuggested minimum hourly rate
Proofreading£29.85
Copyediting£34.70
Substantial editing, rewriting, development editing£39.90
Table of suggested minimum rates from the CIEP [Source]

The price of your project can be affected by various factors, such as how much editing is required, the subject, the length of the project, and the timescale for completion.

Please contact me for further information and an accurate quote for your project.