There is a phrase that for many years in Greece sounded almost as natural as “with or without sugar?”.

“With a receipt or without?”

And usually the second question followed.

“Without, how much?”

100 with a receipt.

80 without.

Simple things.

The customer left happy because they saved 20 euro.

The professional also happy because the transaction suddenly acquired a private character.

And somewhere far away, without having been invited into the discussion, there was also the state.

Which was probably not quite so happy.

If you look at it a little more coolly, this small everyday transaction explains a large part of the logic behind tax evasion.

And no, it is not because we have some special gene.

So, is «without a receipt» really that Greek?

We very much like to believe that certain things happen only here.

Double parking?

We could discuss it.

«I’ll be there in five minutes» when we have not even left the house yet?

Also a strong Greek case.

But tax evasion?

Not quite.

Cash transactions, discounts that raise questions, non-issuance of receipts and attempts to conceal income exist in Italy, Spain, Germany, the USA and many other countries.

Why?

Because wherever there is a transaction, there are also incentives.

The seller wants to keep more.

The buyer wants to pay less.

And the state wants the tax it is due.

Three players.

Only sometimes the first two decide that the game is better played without the third.

The problem starts when it suits both

This is perhaps the most interesting point.

Tax evasion is not always the story of a business owner trying on their own to hide revenue.

Sometimes it is a very simple agreement.

«If we do not issue a receipt, I can give you a better price.»

One pays less.

The other declares less.

Win-win.

Only there is also the state.

So it is probably win-win-lose.

And here the issue stops being merely moral.

It becomes economic.

If a violation offers a significant benefit and the likelihood of being detected is low, some people will be tempted to commit it.

If, however, you begin to change that balance, behaviour begins to change too.

And somewhere here technology enters the story.

Once, a receipt could simply… disappear

Let us go back twenty years.

There is no myDATA.

There are no interconnected POS terminals and cash registers as today.

There is no IRIS.

There are no digital dispatch notes.

There are no digital customer registers.

There are books.

Papers.

Files.

ERP.

And, of course, that drawer in the accounting office that has seen things we will never know about.

The tax administration could discover a discrepancy months later.

Perhaps even years later.

Today the situation is quite different.

The transaction leaves more and more digital traces.

And traces have one bad habit.

They are linked to each other.

myDATA is not just another platform

In 2025, more than 3 billion document transmissions were carried out through myDATA.

Three billion.

If you try to imagine it in folders, we would probably need a bigger country.

What is interesting, however, is not simply the volume.

It is what can be done with this information.

Because next to myDATA there are now POS terminals.

The cash registers.

Electronic invoicing.

IRIS.

Digital dispatch notes.

Digital customer registers.

Suddenly, pieces of information that once sat in different drawers can be placed on the same screen.

And then the questions begin.

The new inspector may never appear in the shop

We usually think of a tax audit in a rather cinematic way.

The door opens.

The inspector walks in.

«Good morning, AADE.»

A small flutter.

They ask for books, receipts, cash.

Only now the audit may have started long before that door opened.

Because a system can see:

How many purchases you have.

How many receipts passed through POS.

What turnover you declared.

How many employees you employ.

What operating expenses you have.

And then it can do something extremely simple.

Ask:

  • “Does it work?”
  • If the answer is “not really”, then perhaps someone should take a closer look.

That is the big change.

Not that we have acquired more fines.

We have acquired more dots that can be connected.

And it seems that the dots are starting to connect

The 2025 figures are interesting.

The AADE carried out 7.671 VAT audits using POS and myDATA data.

In 2024 the corresponding audits were 2.801.

An increase of almost 174%.

But the most striking thing is not that.

The assessments from those audits were around EUR 2.1 million in 2024.

2025?

Around EUR 47.9 million.

Something changed.

And it probably was not that the inspectors suddenly started drinking more coffee.

It was the data.

And now for the twist: we are no longer as “bad” as we think

This is where the story becomes even more interesting.

Because if you ask ten Greeks which country has a huge problem with tax evasion, eleven will probably answer “Greece”.

We have a slight weakness in self-criticism.

In VAT gap terms, however, the picture has changed.

The latest comparable European data place Greece at around 11.4%.

In 2019 it was around 24%.

Almost half in a few years.

Did we solve tax evasion?

Obviously not.

But something very interesting happened.

The rules began to change.

And with them, behaviour began to change too.

Because in the end you do not need to change the Greek

Here comes a bit of game theory.

Do not be alarmed.

There will not be an exam at the end.

Let us say someone is thinking of hiding a transaction.

There is the gain they will have if they do so.

There is the probability of being detected.

And there is the cost if they are detected.

In very simple form:

  • Tax evasion benefit > probability of being caught × cost if caught
  • If the first side seems much larger, the offence looks more attractive.

But if the probability of detection increases significantly, the equation changes.

And with it, the decision changes.

The person’s character did not suddenly change.

The incentives changed.

Of course, the state cannot ask only for more audits

Here we need to be fair to the other side as well.

You cannot have a tax system that is complicated, with constant changes, many obligations, high charges and endless bureaucracy, and the only answer be:

  • “We will put in another platform.”
  • Because then there is a serious risk that you do not have digital transformation.

You simply have bureaucracy with a password.

The real solution is much simpler in theory and considerably harder in practice:

To make it easy to be lawful and difficult to be unlawful.

Simple rules.

Stability.

Reasonable charges.

Automation.

Less hassle for the compliant.

And a much greater probability of detection for anyone who systematically tries to stay outside the system.

Greek ingenuity may in the end be simply… mathematics

We like grand explanations.

“That is how we Greeks are.”

“That is our mentality.”

“This nation does not change.”

And yet.

The same person who once asked:

  • “Without a receipt, how much?”
  • today pays with POS.

Tomorrow they may pay with IRIS before the bill even reaches the table.

DNA did not change.

A different person did not wake up.

The environment around them changed.

And that may be the most hopeful part of the whole story.

You do not need to change an entire nation to change an economic behaviour.

You need to design the game better.

Better rules.

Better incentives.

Better cross-checks.

And a system in which being lawful is simpler than trying to hide.

So, in the end, the famous «Greek genius» may not be quite so mysterious.

A little economics.

A little game theory.

Lots of data.

And since we are in Greece…

a ouzo never hurt anyone.