Linked account for Early Payments Sales Discount in Receivables

SOLVED

Our company have set up an early payment discount for people that pay within a set number of days (re Receivables).

I am relatively new to all this but managed to get the early payment entered - trouble is the module won't accept it because it doesn't have a linked account.  When I went to set up a linked account, there is an account code in there for Principal Bank Account (1080) and Accounts Receivable (1200).  My gut instinct was to link it to Principal Bank Account but would appreciate if anyone could confirm this is the right thing to do.