How to calculate Spanish VAT: adding it, removing it, and not getting it wrong

Two operations, not one

There are only two things you can want to do with VAT, and it is worth being clear which is which before touching a calculator.

Adding VAT. You have the taxable base and want the total.

total = net × (1 + rate ÷ 100) €1,000 × 1.21 = €1,210

Removing VAT. You have the final price and want the net.

net = total ÷ (1 + rate ÷ 100) €1,210 ÷ 1.21 = €1,000

In both cases the VAT amount is simply the difference between the two figures: €210. It is not a third calculation, and working it out separately is the quickest way to end up with three numbers that disagree by a cent.

The mistake of subtracting the percentage

This is far and away the most common error. Subtract 21% from €1,210 and you get €955.90. The real net is €1,000. You have lost €44.10 along the way.

The reason is straightforward: the 21% was calculated on 1,000, not on 1,210. Taking 21% off the total removes 21% of a larger amount than the one it was calculated on, so it takes off too much.

The operation that undoes a multiplication by 1.21 is a division by 1.21. Never a subtraction.

The three divisors worth remembering

To get the taxable base from a final price, by rate applied:

If you want the VAT amount rather than the net, at the general rate it is roughly 17.36% of the total (0.21 ÷ 1.21). It is an unmemorable number, which is precisely why so many people get it wrong trying to do it in their head.

What you multiply is not the price: it is the base

This is where almost every VAT calculator stops short. It assumes you already know the taxable base and only need to multiply. But the base is not "the price of the thing": it is a concept defined in article 78 of Law 37/1992¹, whose paragraph Uno describes it as the total amount of the consideration, including consideration coming from third parties and not only from the customer.

Paragraph Dos lists what goes into that total even when it appears on a separate invoice line:

• commission, carriage and transport charges, insurance and premiums for advance performance (art. 78.Dos.1.º);
• the amount charged for packaging and containers, including returnable ones (art. 78.Dos.6.º);
• subsidies directly linked to the price, meaning those set per unit delivered or per volume of service and fixed before the supply takes place (art. 78.Dos.3.º);
• debts assumed by the customer as part of the payment (art. 78.Dos.7.º).

And paragraph Tres lists what stays out:

• compensation payments which by their nature do not remunerate a supply of goods or services;
• discounts and rebates granted before or at the same time as the supply and by reference to it;
• sums paid in the customer's name and on their behalf under an express mandate, known as suplidos, with the trade-off that whoever pays them cannot deduct the VAT on them.

There is an exception buried in the second paragraph of art. 78.Dos.1.º that is worth knowing: interest for deferred payment relating to a period after delivery is not part of the base, provided it is stated separately on the invoice and does not exceed the usual market rate. A surcharge for paying in instalments can therefore fall inside or outside the VAT base, and what decides is not its name but when it accrues and whether it is itemised.

Delivery and the suplido: €6.30 for a name on an invoice

A garage repairs your car: €400 of labour, €250 of parts and €30 of courier. There are two lawful ways to invoice that, and they do not produce the same tax.

If the garage books the courier in its own name and recharges it, the €30 is consideration and goes into the base (art. 78.Dos.1.º). If the garage orders it in the customer's name and on their behalf under an express mandate, that same €30 is a suplido and stays out (art. 78.Tres.3.º), on condition of evidencing the actual amount and of giving up the deduction of any VAT charged on it.

The same money changes hands either way. The difference in tax is €6.30, and it is decided by whose name appears as the customer on the courier's invoice.

Tax on tax, with one exception

Art. 78.Dos.4.º puts into the base taxes and levies of any kind falling on the same transaction, except VAT itself¹. And it says so expressly of excise duties: the alcohol duty on a bottle of gin, or the hydrocarbon duty on a tank of diesel, sits inside the base on which the 21% is then calculated.

In other words: you pay VAT on the excise duty. That is not anybody's error, it is the rule.

The one exception the law bothers to name is the special tax on certain means of transport, the registration tax, which stays outside the VAT base. It is worth not confusing it with the municipal road tax, which is a different thing: the difference is set out in what Spanish road tax is.

If nobody said whether the price included VAT, the law says

This is the real version of the question, the one people actually search: "I have been given a price and it says nothing about VAT, do I multiply or divide?". The VAT Act answers it, and it answers it in two opposite ways depending on who the customer is.

The general rule (art. 78.Cuatro). Where the VAT was not expressly passed on in an invoice, the consideration is taken not to have included it. The price is the base, and VAT is added on top. With two carve-outs the paragraph itself lists: cases where expressly passing the tax on was not compulsory (the typical one being a sale to a final consumer) and the art. 78.Dos.5.º situation.

If the customer is a public body (art. 88.Uno, second paragraph). It is always taken that the supplier, in framing its economic proposal, even a verbal one, has already included the VAT within it. The tax is then itemised separately where appropriate, without the total contracted amount increasing as a result.

Two opposite presumptions, ten articles apart, in the same statute. Quote a company €10,000 without mentioning VAT and you can invoice €12,100. Quote a town hall the same figure and you have quoted €8,264.46 of net plus €1,735.54 of VAT, and the town hall will pay €10,000.

Why a till receipt forces you to divide

The reason VAT has to be stripped out so often is not that people are careless: it is that the law allows the piece of paper not to carry the base.

A full invoice must state, under art. 6 of the invoicing regulation (Royal Decree 1619/2012)², the unit price excluding tax and any discount not already included in it (letter f), the rate or rates applied (letter g) and the VAT passed on, shown separately (letter h). With that there is nothing to divide: the base is already written down.

A simplified invoice, which is what the bakery hands you, is only obliged to carry the rate applied (art. 7.1.f, where the words «IVA incluido» are additionally optional) and the total consideration (art. 7.1.g). The VAT amount appears only if the customer is a business and asks for it, in which case art. 7.2 requires it to be shown separately.

So the receipt gives you, by legal design, exactly the pair of figures that forces a division: a rate and a total, with no base. The reverse operation being needed so much is not an accident of retail, it is in the minimum content the regulation lays down.

Invoices with several rates

If an invoice mixes items at 21% and 10%, there is no average rate that works for the whole. You have to split the lines by rate, calculate the base and the VAT for each block, and add up at the end. And it is not advice: art. 6.2.c) of the invoicing regulation requires the part of the taxable base corresponding to each rate to be specified separately, and the second paragraph of art. 7.1.f) imposes the same on a simplified invoice.

That leaves the hard question, the one nobody answers: what if they were sold for a single price? A hamper, a set menu, a bundle. Art. 79.Dos gives the method:

Where, in a single transaction and for a single price, goods or services of differing nature are supplied [...] the taxable base corresponding to each of them shall be determined in proportion to the market value of the goods supplied or the services rendered.

A €60 hamper containing wine with a market value of €30 (21%) and food with a market value of €20 (10%) splits 60% / 40%:

Look at the result: €9.96 on €60 is 16.60%, a rate that does not exist in the VAT Act and cannot lawfully be applied to anything. A flat 21% on the hamper would have charged €12.60, which is €2.64 too much. That is why correct invoices break VAT down by rate rather than giving a single figure: it is not formalism, it is that the aggregate calculation does not exist.

The second paragraph of art. 79.Dos sets the limit: the apportionment does not apply where those goods or services are ancillary to a principal supply. The box, the ribbon and the delivery of the hamper are not apportioned, they follow the main product.

The retail equivalence surcharge changes the divisor

This is where 1.21 fails silently. If your supplier sells to you as a retailer under the recargo de equivalencia regime, the invoice carries two percentages on the same base: the VAT and the surcharge of art. 161¹.

A €1,000 base at the general rate becomes €210 of VAT plus €52 of surcharge, and the invoice totals €1,262. Apply the usual 1.21 divisor to that €1,262 and you get a base of €1,042.98: nearly €43 too much per thousand. The surcharge is not a higher rate of VAT, it is a separate tax travelling on the same invoice, and it has to go into the divisor. Who is inside that regime, why a retailer cannot charge it to their customer and when it pays are in what the equivalence surcharge is.

Discounts: before is one thing, after is another

A 10% discount granted at the moment of sale and a 10% discount granted three weeks later produce exactly the same total. The arithmetic is commutative and there is no trick in that. What changes is the paperwork, and it is not trivial.

• Before or at the same time (art. 78.Tres.2.º): the discount never enters the base. It is invoiced already discounted, and art. 6.1.f) of the regulation requires it to be shown if it is not built into the unit price.
• Afterwards (art. 80.Uno.2.º): the base is reduced by the amount of the properly evidenced discount. That is a modification of the taxable base, which needs a rectifying invoice and corrects the quarter already filed on the quarterly VAT return.

And there is one case where the number does change: the second paragraph of art. 78.Tres.2.º takes out of the rule any discount that in reality remunerates other transactions. A "discount" that is really paying for shelf placement reduces nothing: it stays in the base and is itself a taxable supply in its own right.

Invoices in another currency

Art. 79.Once leaves no room: where the consideration is fixed in a currency other than the Spanish one, the selling exchange rate set by the Banco de España in force at the moment the tax accrues applies.

Three things are out of the equation, and all three are the ones people reach for out of convenience: the date you pay, the rate your bank or card gives you, and the month's average rate. The euro taxable base of a dollar invoice is fixed on the day of accrual, and later exchange differences are a financial result of yours, not a VAT correction.

A supplier who forgot the VAT has one year

And only one. Art. 88.Cuatro says, in a single line, that the right to pass the tax on shall be lost once one year has elapsed from the date on which the tax accrued. If work was invoiced to you on 15 March 2025 without VAT and the supplier turns up in April 2026 asking for the 21%, the right to charge it is gone.

Two rules from the same article complete the picture, and both work in favour of whoever receives the invoice:

• art. 88.Cinco says the customer is not obliged to bear the tax before it accrues, so a deposit does not oblige you to advance tax on something not yet delivered or performed;
• art. 88.Seis classes disputes over passing the tax on, both as to whether it is due and as to how much, as matters of a tax nature. It is not a civil argument between the two parties: it goes to the economic-administrative tribunals.

A worked example with real numbers

A printer invoices a company for a catalogue. €2,000 for the work, €80 of transport, a 5% early-payment discount agreed in the order, and nothing said about VAT in the quote.

1. The base. Transport goes in (art. 78.Dos.1.º): 2,000 + 80 = €2,080. The discount is prior and stays out (art. 78.Tres.2.º): 2,080 − 104 = €1,976.
2. The rate. A commercial catalogue is none of the goods art. 91.Dos.1.2.º takes to 4%, nor does it appear in the art. 91.Uno lists, so the general rate applies by default: art. 90.Uno taxes everything at 21% save as provided in the following article.
3. The VAT. 1,976 × 0.21 = €414.96. Total €2,390.96.
4. Who carries the VAT. The quote did not mention it and the customer is a company, so art. 78.Cuatro applies: the €1,976 was the base and the invoice goes up. Had the customer been a town hall, art. 88.Uno would have made that €1,976 the total, with €1,633.06 of base and €342.94 of VAT already inside.
5. In reverse. Anyone seeing only the €2,390.96 total recovers the base by dividing by 1.21, not by subtracting 21%: 2,390.96 ÷ 1.21 = €1,976.00. Subtracting would give €1,888.86, which is €87.14 short.

You can check any of these steps in the VAT calculator, and if what you need is a whole quarter rather than one invoice, the place for that is the quarterly VAT return.

Two things that have changed recently

The art. 91 rates move, and two recent changes throw out any guide written a couple of years ago:

• Olive oils are at 4%, not 10%. Art. 2 of Royal Decree-law 4/2024³ moved them into the super-reduced rate with effect from 1 January 2025, and the change is permanent, not one of the temporary cuts of 2022 and 2023.
• Soft drinks, juices and fizzy drinks with added sugars or sweeteners are at 21%, excluded from the 10% food rate by art. 69 of Law 11/2020⁴ and indefinitely so. A juice with no added sugars is still at 10%. Two bottles from the same shelf can carry different rates.

Which rate applies to which product is a separate question, and it has its own page: Spanish VAT rates. And if the transaction is in the Canary Islands, Ceuta or Melilla, art. 3 of the VAT Act puts them outside the territorial scope of the tax⁵, so nothing on this page applies to them: there you calculate IGIC or IPSI, which are different taxes rather than different rates.