Allow Choice between Royal Mail Franking Tariff and Royal Mail Standard Tariff
I recently discovered an issue where the business I was setting up the current Royal Mail plugin actually uses Franking Rates rather than the standard rates. https://www.royalmail.com/sites/default/files/royal-mail-franking-wallchart-25-march-2019-40966280.pdf . I know a lot of businesses in the UK will use franking rates as they are cheaper so it would be really useful if the current plugin allowed you to choose which tariff you were using.
Also an option to use ParcelForce's Account Tariff would also be useful -> https://www.parcelforce.com/sites/default/files/3509PFWA4Pricing%20guide09-09-19_ONLINE.pdf