FAQ : I want to set the GL Control in the customer master and supplier master to related party or non-trade debtors or creditors, but the field is greyed off (or disabled ) I am not allowed to change
Answer : You need to create a new user account that is set to the user group [CSP]. Login with the id that is assigned to [CSP]
The GL Control field is now enabled and you can change the GL code.
(Note : For new account only, not allowed if you [Edit] and existing customer / supplier )
Repeat the same for supplier master See Seamless filing