I received an invoice relating to mail charges, what is this for?

We apply a fee for the forwarding of the following mail items: Registered Office and Service Address We charge Royal Mail Postage Rates + 15% for all items that need to be posted outside of the UK. Business Address We charge £0.50 for each item of general business correspondence which is scanned and emailed. We charge Royal Mail Postage Rates + 15% for all items of general business correspondence which are physically forwarded by post within the UK and internationally.