...
Once orders have been placed if the customer has reached the credit days.
Removing Days Credit
Option 1 - using the Export/Import function
Contacts -> Customers -> Import/Export -> Download Current Layouts -> Customers Billing -> Export -> update the Days credit field to 0 and reimport re import the file to BUZ
Option 2 → Using BUZ
Customers → Advanced Search to find required customer → Edit Details → Scroll down to Account Details → Update Days Credit to zero → Save
Import/ Export Customer Details
...