Suppliers and accounting systems do not always calculate amounts the same way. A supplier may round each line before adding tax, while your accounting system adds tax first and rounds the total - so the NET, TAX, and TOTAL captured from the invoice can be a few cents off the amounts Datamolino or your accounting software calculates.

These small differences are normal. The point of this article is to show where Datamolino flags them and which fix to use for each case.

👉 What are the two situations I need to fix?

There are two distinct cases, and each one has its own fix:

Every document has a checksum that compares the amounts read from the invoice (the captured amounts) against the amounts Datamolino calculates from the line items and tax codes. If there is a gap on NET, TAX, or TOTAL, the checksum highlights it before you export.

The checksum rounds amounts to two decimals when comparing. For credit notes, it compares absolute values so that sign differences do not get flagged as mismatches.

👉 Will Datamolino still let me export a small difference?

That depends on the integration and on your tax setting:

A NET-only difference that does not affect TOTAL is not enough to block the export on its own.

When the line items do not add up to the invoice total, the export is blocked until you balance them. The fastest way to do that is to add an adjustment line - Datamolino works out the missing amount and writes it as a single extra line so the document balances.

👉 Where do I find the Add Adjustment Line button?

Open the document and switch to Line items view. The Add Adjustment Line button appears below the line items when a difference is detected. It is only available in Line items view - it does not appear in Summary or Tax Summary view.

👉 What gets written to the adjustment line?

The adjustment line carries the exact difference value. Datamolino populates the line's amount fields with that value and codes it using your folder's rounding defaults:

👉 Is the Adjustment Line available for every accounting integration?

No. It is available for Xero and QuickBooks Online folders. For QuickBooks Online it is hidden for US companies, because QBO US uses a different totals model.

If your line items add up correctly but the tax amount captured from the invoice does not match what Datamolino calculates, an adjustment line does not help - the difference is on TAX, not on TOTAL.

Start by checking whether the tax codes on the line items are correct. A wrong tax code is the most common reason for a TAX mismatch, and changing the tax code lets Datamolino recalculate cleanly.

👉 What if I cannot resolve the difference by changing the tax code?

Switch the document's tax setting to Send exact tax amount, then adjust the amounts manually so they match the invoice. This tells Xero to accept the tax value exactly as Datamolino sends it, instead of recalculating it on Xero's side.

Treat this as an exception for one invoice rather than as your default. With Send exact tax amount, the checksum tolerance is removed - TAX and TOTAL must match exactly, so any future difference is no longer tolerated automatically.

For Xero folders, we recommend keeping Let Xero calculate tax as your default tax setting. With this setting, Datamolino sends the line amounts and Xero calculates the tax on its side. The checksum compares the result against what was captured, so any difference between the captured tax and the calculated tax is flagged on the document immediately - before you export.

The reason to keep this as the default: problems surface up-front, in Datamolino, rather than after the document has already been pushed to Xero. Send exact tax amount is the fallback for invoices where the captured tax is genuinely correct but cannot be reproduced by recalculation.

Learn more about Net vs Total export logic, which controls how amounts recalculate when you edit them.

For QuickBooks Online folders, the Adjustment Line uses a default ledger account and tax code that you set once per folder. Setting these defaults means future adjustment lines are fully coded automatically.

👉 Where do I configure the defaults?

Go to Folder Menu (right side of the screen) > Accounting & Automation > Integration and go to the Adjustment Line Settings block. Choose a Rounding Ledger Account and a Rounding Tax Code. From then on, any adjustment line added in that folder is coded to these values by default.

👉 What happens if I have not set them yet?

Datamolino shows a prompt asking you to choose a Rounding Ledger Account and Rounding Tax Code the first time you try to add an adjustment line. Set them once and the prompt will not return for that folder.