If you recently installed Sage 50 (Peachtree) or installed a Sage 50 (Peachtree) upgrade, the general ledger accounts may not show in the sales invoicing or receipts screen.  This can be fixed within the Sage 50 (Peachtree) options.  From the main menu of Sage 50 (Peachtree), click on Options-Global.  Locate the section called “Hide General Ledger Accounts”.  Take the check mark out of the Accounts Receivable box, click on Ok.  When you go to sales invoicing or receipts, you should now see your general ledger accounts.