Idealpos has two methods of sending Customer Account Sales (Debtors) to MYOB.
Accrual Method – All Debtor and non-debtor sales are sent together to MYOB in a General Journal Entry transaction.
Cash Method – All Debtor sales are sent separately to MYOB to a single Debtor Account.
If your business accounts for GST using the Cash Based Method, and you perform sales to Debtors, then the Global Debtor Account is required to ensure MYOB correctly reports sales and GST.
The Method that's used by Idealpos can be selected by going to: Back Office > Setup > Global Options > Miscellaneous > Financial.
At the bottom of the window next to the GST Accounting label, select Cash or Accrual.