The best way to add a manual adjustment to costs is to add a manual bill and date it prior to your journal start date.
This is so that ScaleXP sees the cost but does not assume there is an associated bill already in your accounting system.
- Go to Journals > Month-End Close and open New supplier bills.
- Click the three dots at the top right and select Add Manual Bill.
Click Select Supplier to choose an existing supplier, or Add Supplier to create a new one. You may wish to create a new "Adjustment" supplier for this purpose.
Create a bill for the adjustment amount, making sure the Bill Date is before your journal start date.
This is so that ScaleXP knows the bill does not already exist in your accounting system for the journaled month.