Why hasn't Poland joined the euro yet, even though it still has its own currency?
Good question — and you're not the only one asking it

The short answer: Poland MUST adopt the euro at some point, but for now, it consciously doesn't want to.
The longer (more interesting) answer

Poland & the euro: what's the deal?

Legal
Poland has been an EU member since 2004.
This means the country has obligations to join the eurozone at some point.
However: no fixed date has been agreed upon.

So: postponement is permitted, cancellation is not (in theory).

Why Poland doesn't want the euro yet

Own currency = own monetary policy
Poland uses the Polish złoty (PLN).
This offers advantages:
Own interest rate
Own exchange rate
Central bank can respond quickly to crises

During crises (2008, COVID, Ukraine war), Poland could:
weaken the zloty → exports became cheaper
implement an independent interest rate policy
With the euro, this wouldn't be possible.

Better absorption of economic shocks
Poland has a different economic structure than, for example, Germany or the Netherlands:
Lower wages
Different inflation patterns
Faster growth
With the euro:
One interest rate for all of Europe
This often doesn't fit well with Eastern European economies

Many Polish economists point to Greece as a warning.

Inflation Fear
To join, Poland must meet the Maastricht criteria, including:
Low inflation
Budget deficit < 3%
Stable exchange rate
Poland regularly struggles with:
Higher inflation
Budgetary tensions
The fear:
“Euro introduction → price increases for citizens”
(This fear is also strong among the population.)

Politics & Public Opinion
Support for the euro is low to mixed
Many Poles see the złoty as:
a symbol of sovereignty
an economic safety net
Conservative parties, in particular, say:
“Why give up something that works well?”

In many polls, less than 50% support the introduction of the euro.

It just works… for now
To be fair:
Poland is experiencing strong economic growth
Unemployment is low
Exports are doing well
Foreign investment continues to flow
So the feeling is:
"Why change if it's not necessary?"

Why other countries and not Poland?
Comparison:

Slovakia → euro (2009)

Baltic States → euro
But:
These economies are smaller
More intertwined with the eurozone
Less internal support for its own currency
Poland is large, economically diverse, and less dependent.

In summary
Poland doesn't yet have the euro because:

it wants to maintain its own monetary policy

the złoty cushions economic shocks

there is fear of inflation and price increases

there is little political and social support

it doesn't feel the need for accession is urgent

However: legally, the door remains open — the euro will probably arrive someday.
If you'd like, I can also:
explain exactly what Poland needs to do to join
or compare it with the Czech Republic/Hungary
or predict when euro adoption would be realistic
Just say
