Clients and suppliers are not strictly distinguished in the SimplBooks system since one company can be both for your company.
1. Client/supplier details can be changed on the client information sheet.
Different segments of the client/supplier information sheet display related contacts, contact details, notes and sales and purchase invoices and on the right you can find the operations menu for the client/supplier.
Available operations include adding a new invoice for the client, saving new payment terms and conditions (under “Change the client/supplier”) or deleting the client.