SAP B1 blog

That Rounding account is a predefined G/L account in SAP Business One to which rounding differences are posted. These differences arise, for example, from the conversion of amounts into different currencies. Currencies or by applying rounding rules in vouchers.

If you go to the company details under Administration > System initialisation > Company details > "Accounting data" tab select the rounding method "By currency", rounding differences may occur. The difference between the original amount and the rounded amount is displayed in the voucher in the "Rounding" and automatically posted to the previously defined rounding account.

The rounding account is configured under Administration > Definition > Financial accounting > Account determination ledger accounts > General.