That 2 % for paying by card has been illegal since 2018

You get a six-hundred-euro repair done and, when you take out your card, the garage adds 2 %: twelve euros more. In Spain that has been illegal since 2018, and the garage knows it or ought to.

The rule has two pieces. The European one is Regulation (EU) 2015/751, which capped the interchange fee — what the merchant's bank pays your card's bank on every purchase: 0.2 % on consumer debit cards and 0.3 % on credit cards. The Spanish one is Royal Decree-Law 19/2018 on payment services, whose article 35, paragraph 3, says this and little more: the payees of payment transactions may not require the payer to pay additional charges or fees for the use of any payment instrument whatsoever. In plain words: whoever is taking the money cannot charge the person paying extra for the way they pay. Three lines, and they also cover transfers and direct debits in euros.

The sums, done. On that six-hundred-euro repair, the interchange fee on a debit card is 0.2 %: one euro twenty. Adding the margin the garage's own bank keeps, taking your card payment costs it between two and four and a half euros. The twelve it passes on to you is between three and six times that. And in the bar next door, where the typical surcharge is fifty cents on a twelve-euro set lunch, the arithmetic is worse still: 4.2 % of the bill for a transaction that costs between five and ten cents.

Six situations, and who is right in each:

1. The garage with its 2 %: illegal.

2. The bar that adds €0.50 "for the card machine". That too. And the sign stuck on the till does not fix it: warning about a banned charge does not make it lawful.

3. The gym charges you a fee for setting up your monthly direct debit. Same article, same answer: euro direct debits and transfers within the SEPA area, the European zone for euro payments, fall under 35.3.

4. The hotel puts 3 % on your bill for paying with a corporate card or one issued outside the European Economic Area. Those cards do fall outside the European interchange cap, which is why many hotels think they can. Spain took the option the directive offered and banned surcharges on any payment instrument whatsoever, with no such exception. The 3 % does not stand either.

5. The bakery sets a five-euro minimum for card payments. That is not a surcharge. A shop may decide which payment methods it accepts, as long as it says so before you buy. What it may not do is accept the card and then charge you for it.

6. The plumber tells you it comes out cheaper in cash. Article 35 is no use to you here, because this is not about means of payment: VAT is due however you pay, and what he is offering you is not to issue an invoice. The one left with no invoice, no guarantee and nothing to claim on is you.

And one way to recognise it with no knowledge of the law at all: if the amount changes after you have decided to pay — at the card machine, on the last checkout screen, at the moment of signing — that is a surcharge. If the number was already on the menu, the quote or the label, that is a price, and the price is the business's to set. A restaurant may charge twelve euros forty for its set lunch simply because it feels like it. What it may not do is charge twelve and add forty cents when you take out your card.

What you can do this week, in order:

First, ask for the surcharge to appear itemised on the receipt or the invoice, with its name written on it. It tends to vanish right there.

Second, if they do write it, pay and keep the paper: with no receipt, the consumer office files the complaint.

Third, ask for the complaints form. Every business in Spain is obliged to have one and to hand it over free.

And fourth, take it to your town hall's consumer information office or to your region's consumer affairs directorate, which are the bodies that fine the business. The Bank of Spain supervises banks, not the café.

Before any of that, today: type "Real Decreto-ley 19/2018" into the search box of the Spanish State Official Gazette, open article 35 and photograph paragraph 3. It is three lines and it fits whole on a phone screen.