Go to Setup > Customer/Vendor > Business Partner, then click "New".
The page will refresh, displaying fields for entry of details belonging to the Business Partner you want to register.
Firstly, enter the Business Partner's Name, UEN and Country.
BP Code is the unique identifier of each Business Partner in the system.
It is recommended that you decide on a standard format.
(e.g. "CO-001, CO-002... " for Customers, "SO-001, SO-002..." for Suppliers, and "CS-001..." for entities who are both a Customer and a Supplier)
Next, enter the address details of this Business Partner.
Address Code can be kept simple, like "1, 2, 3..." or "a, b, c..." or same as Address Name.
Next, indicate whether this Business Partner is a Customer, a Supplier, or both; by selecting the group in the respective segment(s).
The fields underneath the selected group(s) will be unlocked.
Term, Currency, Tax and Address are fields where you may set a default value.
Any values set in these fields will automatically appear during document entry for this particular Business Partner, though you may choose to change them before saving that particular document.
Lastly, follow this guide to set the Peppol ID of your Business Partner.