XBert Type: Standard
Accounting Software: Xero, QuickBooks Online
Country Restriction: the United Kingdom only
Risk Type: Tax Risk
Business Function: Purchases
Overview
This XBert checks that the VAT recorded on a supplier bill actually matches the VAT rate applied to it. When the VAT keyed onto a bill does not equal the rate multiplied by the net amount, the figures on your VAT return can be wrong. Catching this before you file helps keep your input VAT accurate and your records clean.
What it does
It looks at each supplier bill that has standard-rated lines and works out the VAT those lines should carry. It compares the VAT you should expect (net amount multiplied by the VAT rate) against the VAT actually keyed onto the bill. If the two materially disagree once the whole bill is added up, it raises this XBert.
How it works
For every standard-rated line on a bill, the expected VAT is the net amount times the VAT rate. XBert totals the expected VAT and the keyed VAT across the whole bill, then compares them. It only raises an alert when the difference is genuine and meaningful, not a rounding penny.
To avoid false alarms, it deliberately ignores several situations:
It adds up the whole bill before comparing, so VAT booked onto a single line of a multi-line bill (rather than spread line by line) still balances out and does not trigger.
It skips bills that carry little or no VAT despite standard rates. That is a different signal (missing VAT or a reverse-charge situation), not a calculation error.
It skips domestic reverse-charge lines, such as CIS reverse charge, where £0 VAT on the bill is correct by design.
It ignores zero-rated, exempt and no-rate lines, because no VAT is expected on those.
A small materiality threshold and percentage tolerance absorb ordinary rounding and currency differences.
Example/Use Case
James, a bookkeeper at a building firm, enters a bill from a materials supplier for £4,000 net at the standard 20% rate. The VAT should be £800, but the supplier's invoice was hand-typed and the VAT field was overtyped as £80 by mistake. XBert compares the keyed VAT of £80 against the expected £800 and raises this alert, showing a £720 gap. James opens the bill, corrects the VAT to £800 to match the supplier's invoice, and his next VAT return now reclaims the correct input VAT instead of understating it by £720.
Accounting software
This XBert runs on Xero and QuickBooks Online.
Which countries it supports
This XBert applies to the United Kingdom only.
Processes
Business area: Purchases (Accounts Payable). To resolve this XBert:
Open the flagged supplier bill and find the original invoice or PDF.
Check the VAT rate applied to each standard-rated line against the supplier's document.
Recalculate the VAT for each line as net amount multiplied by the VAT rate, and compare it to the VAT keyed onto the bill.
Correct the VAT amount or rate so the bill matches the supplier's invoice. If the VAT was deliberately overridden, confirm it is genuinely correct.
If the bill is a reverse-charge or zero-rated transaction, make sure the correct tax code is applied so the VAT treatment is recorded properly.
Where the supplier's own invoice is wrong, request a corrected invoice before reclaiming the VAT.
Once the bill is corrected, mark the XBert as resolved.