Why do shops within airport terminals scan your boarding card?

In the Dutch airport shops there is the rule that only outbound passengers may buy goods in the 'duty free' shops. They are not really duty free anymore but the rule still stands. All outgoing passengers are allowed to buy, so it is not nationality nor destination.

I guess that those airports where they do not have that restriction use the boarding cards as marketing tool, that is the only rule I see.

You can buy food in airport restaurants as incoming and outgoing passenger, so they do not need to ask for boarding cards. I have never tried to buy a bottled drink or a small snack as incoming passenger, but on some airports they even ask for your boarding card for those.

I am not sure how universal the VAT argument is, as this process is applied at Dubai Airport as well (where this is no concept of VAT).

At Dubai, they scan your boarding card for the following:

1. To know your destination country; in case there are any customs restrictions on the goods you are buying. Usually done for spirits/alcohol/perfumery/tobacco products; but also done for electronics at times.

2. To make sure you are a passenger in transit and not some contractor, etc. who are restricted on the purchases they can make (they have to show special passes to carry goods out of the terminal).

3. To gather statistics on the types of goods people are purchasing by destination; however this sort of data gathering is not restricted to duty-free shops it is almost universal across any retail business.

I have only noticed this at the duty free shops; and not at the restaurants/food service businesses.

Without knowing exactly which shops and items, it is hard to tell.

I would suspect it has something to do with duty-free shopping, where you have to show proof that you are actually leaving and taking the items with you. Duty does not apply to everything you might purchase, and certainly not to food or drink you are going to consume on the spot.

It's to do with vat. All the stores charge you the full price as they would on the high street. You pay the vat. They claim it back. Big fiddle. You lose. They win. You can refuse to show your card though.

At least in some airports, this is unrelated to duty-free or other taxation issues. Airlines get rebates from the airport based on the amount that their passengers spend in airport shops.

Many European airports have a very large proportions of low-cost flights, and most or almost all flights are within the EU. While the sticker price of the flights is very cheap, passengers spend proportionately large amounts on food and drink, gifts and souvenirs, travel necessities and services within airports. This represents lots of revenue for airport concessions, which often sell at markups compared to non-airport branches, or have more expensive goods available. They in turn have to pay large rents to the airports.

Airlines see some of this money, in the form of rebates against airport charges. Scanning boarding cards is done to allocate this money. Airlines which bring in higher-spending passengers get back more money, this is considered fair, since the net cost to the airport of these passengers is lower.

I believe the reason that passengers go along with it, is that like many of the respondents above, they assume that it has something to do with tax or duty.