How an invoice total is calculated
Every invoice starts from the taxable base: the price of what you sell, before tax and after any discounts. Two separate amounts are then calculated on that base:
- IVA (Spanish VAT), which is added: it is the tax you charge your customer and then pay over to the Spanish Tax Agency in modelo 303 (the IVA return).
- IRPF withholding, which is deducted where it applies: it is an advance on your IRPF (Spanish income tax) that your client pays to the Tax Agency on your behalf (modelo 111) and that you then offset in your income tax return.
Amount due = taxable base + IVA − IRPF withholding. The withholding is always calculated on the taxable base, never on the total including IVA.
IVA rates in 2026
| Rate | Percentage | Applies, for example, to |
|---|---|---|
| Standard | 21 % | Most goods and services |
| Reduced | 10 % | Hospitality and catering, passenger transport and some foods, among others |
| Super-reduced | 4 % | Bread, milk, eggs, fruit, vegetables, olive oil and other basic necessities |
To find out how much IVA is included in a price, divide by 1 plus the rate: a price of €121 including IVA at 21% has a base of 121 ÷ 1.21 = €100 and IVA of €21.
IRPF withholding: 15% or 7%
Professionals who invoice companies or other professionals generally apply a withholding of 15% on the taxable base (IRPF Regulation, art. 95).
The 7% rate for the newly self-employed
If you start a professional activity, you can apply 7% in the year you start and the following two years, provided you did not carry out any professional activity in the year before you started. You have to tell your client in writing, and the client must keep that signed notice.
Invoices to private individuals carry no withholding: the person paying is not required to withhold. The calculator also includes 19% and 0% for other cases; check the AEAT’s table of IRPF withholding rates if you are unsure which one applies to you.
Worked examples
These are the results the invoice total calculator gives for some common cases:
| Taxable base | IVA | IRPF withholding | Amount due |
|---|---|---|---|
| €1,000.00 | 21 % = €210.00 | 15 % = − €150.00 | €1,060.00 |
| €1,000.00 | 21 % = €210.00 | 7 % = − €70.00 | €1,140.00 |
| €1,000.00 | 10 % = €100.00 | No withholding | €1,100.00 |
| €250.00 | 4 % = €10.00 | No withholding | €260.00 |
With zBilling, you don’t have to work it out
When you create an invoice, you choose the IVA rate for each line and, if it applies to you, the withholding; zBilling calculates the base, the tax at each rate, the withholding and the total, and prepares your quarterly IVA summary. Each invoice is also recorded with its hash and QR code under Verifactu.
Frequently asked questions
Is the IRPF withholding calculated on the total including IVA?
No. The withholding is calculated on the taxable base. With a base of €1,000, IVA at 21% and 15% withholding, the withholding is €150 and the amount due is €1,060.
For how long can I apply the 7% rate?
In the year you start your professional activity and the following two years, provided you did not carry out a professional activity in the year before you started and you notify your client.
Do invoices to private individuals carry withholding?
No. The withholding is applied by the payer when they are required to withhold, such as a company or a professional; a private individual is not.
How do I work out the IVA in a price that already includes it?
Divide the price by 1.21 (for IVA at 21%), 1.10 or 1.04: the result is the base, and the difference is the IVA.
Do these calculations replace my accountant?
No. They are guide figures for a single invoice. Your specific situation (IVA scheme, exemptions, equivalence surcharge, type of activity) may change the result.
Official sources
- AEAT — Tipos impositivos en el IVA 2026 (IVA rates, PDF)
- IRPF Regulation (Real Decreto 439/2007), article 95 (consolidated text)
- AEAT — Cuadro de tipos de retención del IRPF 2026 (IRPF withholding rates table, PDF)
These are guide figures only: they do not replace professional advice for your specific situation. More deadlines in the tax calendar.