Reading a Prague exchange board: why 0% commission can still cost you

Walk through the Old Town and you will pass boards like this one a dozen times: a column of flags, a column of numbers and a bright line promising "0% commission". The sign is not lying. It is just answering a question you did not ask.

This is the short course in reading the board. For the basics of exchanging in Prague, the Exchange Act and your rights, see our main guide to changing money in Prague.

Which column is yours?

Every currency on the board has two numbers. They are written from the office's point of view.

• Buy (nákup): the rate at which the office buys foreign currency from you. Hand over euros, get crowns, and this is your number.
• Sell (prodej): the rate at which the office sells foreign currency to you. Arrive with crowns, want euros, and this is your number.

It is an easy mistake, and the board does nothing to stop you making it. If you are leaving with crowns, find the buy column. If you are leaving with euros, find the sell column. Then check the number of units, because some currencies are quoted per 100 and others per one.

Where "0% commission" fits in

An office can earn in two places: a visible fee, and the gap between its buy and sell rates. "0% commission" switches off the first and leaves the second untouched. A fee-free counter with a poor rate can cost you more than a counter with a small stated fee and a fair rate.

The gap is called the spread. Here is a hypothetical example with easy numbers, invented for the maths. Say the official ČNB reference rate for a currency is 20.00 crowns. The board shows buy 18.00 and sell 22.00, with a bright "0% commission" sign in the window.

That round trip is a handy test, and it is the heart of this piece.

Comparing with the ČNB rate

The Czech National Bank publishes official daily rates. You will not get them at a counter, and no office should be expected to match them exactly. But they tell you where the middle is, so you can see how far each side of the board sits from it. Some gap is normal, because that is how an office earns. A big one is your cue to try the next counter.

Look at the whole picture before you decide: banks and offices away from the tourist core usually have tighter gaps than those next to monuments, stations or airports. That is a habit of the market, not a law.

Four small traps

• The wrong direction. An attractive number in the sell column tells you nothing if you are selling.
• Minimum fees. A "no commission" claim next to a minimum charge in small print is a commission for small amounts. Ask.
• Tiers. If the board shows different rates for different amounts, read the row for your amount, not the best one.
• Per 100 versus per one. A rate quoted per 100 units looks nothing like one quoted per unit. Check the quantity column before comparing.

A word on your rights

One line is enough here. Under the Exchange Act, a customer can cancel a cash exchange of up to the equivalent of EUR 1,000 within three hours at the same office and get the original money back (as of 2026; check the Czech National Bank). Keep the receipt; our main guide to changing money in Prague has the detail, and complaints go to the Czech Trade Inspection Authority (ČOI).

When to skip the board altogether

Cards work almost everywhere in Prague, and a bank-owned cash machine usually beats a booth near a monument. Our guide to ATMs in Prague explains how to dodge fees and the "convert to your home currency?" trap. Never change money with someone on the street; our tourist traps guide describes how that goes. For a larger sum, such as a deposit, a bank transfer beats cash; see sending money abroad from Prague. And once the crowns are in your pocket, the Czech koruna for beginners tells you what you are holding.

Frequently asked questions

Does '0% commission' mean a good deal?

No. It means there is no separate fee. The office can still make its profit through a wide gap between its buy and sell rates.

What is the spread on an exchange board?

The gap between the rate at which the office buys foreign currency and the rate at which it sells it. The wider the gap, the more the office keeps.

Which column do I use when I arrive with euros?

The buy column, since the office is buying your euros. If you are leaving with euros, use the sell column.

How do I know whether a rate is fair?

Compare it with the Czech National Bank reference rate on your phone and with one or two other counters. There is no single fair figure.

Can I cancel an exchange I regret?

For cash exchanges up to the equivalent of EUR 1,000, you can cancel within three hours at the same office and get your original money back (as of 2026; check the Czech National Bank). Keep the receipt.

This is a general explainer, not legal or tax advice.