The module 'Sales' online accounting software mKsiegowa.pl, you can define the 'Types of credit worthiness'.
Credibility, according to the preset dictionary, can be assigned to each client (field Customer Status).
For customers who are assigned vocabulary entries with the field Lock Sale? Is set to Yes sales will be locked. Are you trying to issue an invoice to a client receives a message on the screen with the following content:
The referenced account is currently locked recipients. Contact the person responsible for lending
The ability to change the status of the customer can be locked using the powers of the Profile Access of the user.