If you use a cheque cashing service, you will likely be charged a percentage fee, as well as a processing fee. Depending on the provider you choose, this will generally be a percentage fee of between 3% and 6%, and a flat fee of between £1 and £5 per cheque.
This means that the cheapest place to cash a cheque may vary based on the size of the cheque. If you have a larger cheque that needs to be cashed, it’s probably worth finding a cheque-cashing provider that charges a flat fee as opposed to a percentage fee.