An invoice total looks wrong — how to find out why

Almost every "the total is wrong" report turns out to be one of a handful of things. Working through them in this order finds it quickly.

Start by reading the total out loud

An invoice total is assembled in a fixed order:

1. Each line: quantity × unit price
2. Sum of the lines: the subtotal
3. Minus any discount
4. Plus tax, at the rate on the invoice
5. The total

Compare the invoice against that sequence. Whichever step first disagrees with your expectation is where the cause is — which is usually enough on its own.

Check the tax rate on the invoice, not in settings

The most common cause. The rate stored in Settings is the default for new invoices; it is not applied retroactively. An invoice created before you changed the default keeps the older rate, and that is deliberate — a historic document must keep the rate that was correct when it was issued.

Open the invoice and read the rate on it. If it is the old one, that is why, and it is working as designed.

Check whether tax is applied before or after the discount

A discount and a tax rate applied in a different order give a different total. Confirm what you expected: on this invoice the discount is taken off the subtotal, and tax is calculated on the discounted figure.

If your expectation was tax on the full subtotal, the invoice is not wrong — the expectation was.

Check the currency, and the date the rate came from

If the invoice is not in your base currency, two numbers exist: the amount in the invoice's own currency, and the converted amount in your reporting currency.

• The invoice total is in the invoice's currency. That figure is what your customer owes and it does not move.
• The report figure is converted at the rate for the transaction date.

So an invoice can be correct while a report shows a number you did not expect. If a report total looks off but the invoice does not, currency conversion is the likely explanation — and check the invoice's date, since that is the date the rate is taken from.

Check for rounding on long line lists

With many lines, or quantities with decimals, individual line values are rounded before summing. Adding the displayed line values by hand can differ from the stored total by a small amount. If the discrepancy is pennies on a long invoice, this is almost certainly it.

A difference of pennies is rounding. A difference of pounds is one of the causes above.

Check you are looking at the right invoice

More common than it sounds, especially with sequential numbers and duplicated drafts. Confirm the invoice number and the customer. If you duplicated a draft to save time, check that the copy carries the intended dates, rate and currency rather than the original's.

If a report disagrees with the invoices

If individual invoices are right but a report is not, work through:

• Status. Receivables count what is outstanding. An invoice paid but never marked paid still shows as owed — the commonest cause of an inflated receivables figure.
• Date range. Reports are bounded by issue date, and your financial year start determines period boundaries.
• Draft invoices. A draft is not issued revenue and is excluded by design.
• The business selected. With more than one business, each has entirely separate figures. Confirm which is active.

Still wrong?

Note these before asking for help, because they are the first things anyone will need:

• The invoice number, and the business it belongs to
• What you expected, and what is shown
• The invoice's currency and issue date
• The tax rate and discount shown on the invoice

That list usually contains the answer.