how to

How to add tax to an invoice

the short answer

To add tax to an invoice, calculate the tax on your subtotal at the correct rate, then show it as its own line between the subtotal and the total. Decide whether your prices are tax-exclusive (tax added on top) or tax-inclusive (tax already in the price) and label it clearly. Always state the tax name and rate — VAT, GST or sales tax — so the customer can see exactly what they're being charged.

Adding tax to an invoice comes down to charging the right tax for where you trade, deciding whether your prices include it or add it on top, and showing the breakdown clearly.

This guide walks through choosing the correct tax, the difference between tax-exclusive and tax-inclusive pricing, and how to handle more than one tax line on a single invoice.

20%the UK's standard VAT rate, while GST and US state sales-tax rates commonly fall between 5% and 15% — so showing the rate explicitly avoids confusionSource: Sage

Pick the right tax for where you trade

The tax you add depends on your country and registration. VAT applies in the UK and EU; GST applies in Australia, New Zealand, Canada, India and Singapore; sales tax applies in the US, often varying by state and sometimes by city. Only charge a tax if you're registered to collect it — never add VAT or GST if you aren't registered.

Tax-exclusive vs tax-inclusive

Tax-exclusive pricing shows your price first, then adds tax on top — common in B2B and US invoicing. Tax-inclusive pricing means the headline price already contains the tax, which you then show as a portion of it — common in UK/EU consumer pricing. The maths differs, so label which method you're using.

For example, tax on top (exclusive) looks like £100 + 20% VAT = £120 total; tax included (inclusive) looks like a £120 total of which £20 is VAT. To find the tax inside an inclusive price at 20%, divide the total by 6. Either way, always show the subtotal, the tax line, then the grand total.

Handling more than one tax line

Sometimes a single invoice carries multiple tax lines — different VAT rates on different items, or a state plus a city sales tax. Show each one separately with its own rate and amount so the breakdown is transparent and reclaimable.

invoiceme adds any number of named tax lines — VAT, GST or sales tax — and lets you set each one as inclusive or added on top, calculating the amounts automatically so the totals always reconcile.

how it works

  1. 01

    Choose the correct tax

    Identify the right tax for where you trade — VAT in the UK/EU, GST in Australia/NZ/Canada/India/Singapore, sales tax in the US — and only charge it if you're registered to collect it.

  2. 02

    Decide inclusive or exclusive

    Set whether your prices are tax-exclusive (tax added on top, e.g. £100 + 20% = £120) or tax-inclusive (tax already in the price, e.g. £120 of which £20 is VAT), and label which you're using.

  3. 03

    Calculate and show the tax line

    Work out the tax on your subtotal at the correct rate and show it as its own line between the subtotal and the grand total.

  4. 04

    Split out multiple taxes

    If more than one tax applies — different VAT rates, or a state plus a city sales tax — show each separately with its own rate and amount so the breakdown stays transparent and reclaimable.

frequently asked

How do I work out the tax already inside an inclusive price?
Divide the gross amount by (1 + the rate). For 20% VAT, divide the total by 1.2 to get the net, then subtract to find the VAT — or simply divide the gross by 6. For 10% GST, divide the gross by 11 to find the tax portion.
Should I show tax as a separate line?
Yes. Showing the subtotal, tax and total as separate lines is standard practice and, for VAT-registered businesses, generally required. It lets the customer see and, where eligible, reclaim the exact tax charged.
What if some items are tax-exempt or zero-rated?
List exempt or zero-rated items separately and apply a 0% rate or mark them exempt, so the taxable and non-taxable amounts are clear. Mixing them into one line makes the invoice hard to verify and can cause tax errors.

Published June 13, 2026 · Last updated June 16, 2026

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