Royal Mail have various ways you can use Shiptheory, the current easiest route is via Netdespatch.
Netdespatch were aquired and are part of the Royal Mail group.
If we request API details for you, we'll add them to your account as soon as we have them and let you know.
If you already have API details and wish to add them yourself, see below.
Firstly navigate to https://shiptheory.com/royalmailnd/edit/ where you'll be able to complete the relevant fields and test out your connection details
Royal Mail Username
This is the username given to you by Royal Mail's Netdespatch team
Royal Mail Password
This is the password given to you by Royal Mail's Netdespatch team
This is the account number given to you by Royal Mail's Netdespatch team
Specify the time of your last collection with Royal Mail. Your collection time dictates the last time you can book something in for collection. Thus if you book shipments for the following day late at night, we suggest setting this time as 23:50. Please make sure the time you specify is in the 24 hour format, HH:MM . Eg. 17:00 would be for 5pm.
Description of Goods
This is used primarily in exporting, a general description of the category of goods you sell, eg. 'Sporting goods'