VAT on quotes and invoices
Set your VAT registration and number, choose the VAT rate per line, and see how Engineer OS calculates and rounds VAT.
Updated 10 October 2026
Your VAT settings
Go to Settings → Company:
- VAT registered: tick this if your company is registered for VAT.
- VAT number: e.g. GB123456789. It's printed on your quotes and invoices as "VAT No".
If you're VAT registered
- Every line has a VAT % column. New lines on quotes and invoices start at 20%.
- Quotes, invoices and PDFs show a Subtotal, VAT and Total.
- Your VAT number appears in the PDF header.
If you're not VAT registered
- The VAT column and VAT totals are hidden, and every line is charged at 0%.
- PDFs say "Not VAT registered" at the bottom.
Setting the rate per line
VAT is set on each line, so one document can mix rates: for example, 20% on parts and labour and 0% on a zero-rated item. Type the rate into the line's VAT % box. Any rate from 0 to 100 is accepted.
Invoices created from a job start every line at 20%. Check and change the rate before sending if that's not right for the work.
Engineer OS doesn't handle the construction industry domestic reverse charge or CIS deductions. If those apply to a customer, raise that invoice in your accounting software instead.
How VAT is calculated
For each line:
- Line subtotal = quantity × unit price
- Line VAT = line subtotal × VAT rate
- Line total = subtotal + VAT
Each line's subtotal and VAT are rounded to the nearest penny. The document totals are the sum of the lines. Because VAT is rounded per line rather than on the total, the VAT figure can occasionally differ by a penny from a calculation done on the grand total.
All amounts are in pounds sterling (GBP).
Xero and QuickBooks
When you push an invoice to Xero, lines with VAT are sent with Xero's 20% standard-rate tax type and lines at 0% with no VAT. If you use other rates, check the VAT on the invoice in Xero after pushing.
Still stuck? Email support@engineeros.uk