Dfyjkt

If I entered the Schengen area with a non-European passport. But I also posses a Schengen passport. Will staying over 90 days cause any troubles?

I have spoken with the migration department of the airport and they told me it's ok and that I have the right to stay over 90 days without exiting since I am Schengen citizen. But this time I would have to use the European passport to exit after the 90 days.

The question is: will my other passport having only an entry stamp but no exit cause me problems later on, if I am travelling without my European passport?

Both coming to Europe but specially visiting non-European countries: will non-European countries be paying attention that this passport has only an entry stamp to Europe but no exit? If they do notice will it suffice to explain it, or will I always have to carry both passports to prove that I was allowed to exit Schengen without a stamp.

I could always just do a same day trip to the UK to get the exit stamp if this means avoiding having troubles using my other passport later on. But I would rather avoid waisting money and time if not really necessary

In general, border guards in third countries have no business trying to determine based on your passport if you have complied with the Schengen rules in earlier visits. Passports don't consistently contain enough information for them to do that -- for example, non-EEA nationals with residence permits in a Schengen country will routinely have widely separated Schengen entry and exit stamps in their passport, and I haven't heard about anyone needing to carry around their long-expired residence permits just for the purpose of satisfy third-country border guards' curiosity.

So in general you probably don't need to worry about entering non-EEA countries.

On the other hand, if you leave the Schengen area without bringing your EEA passport, you can probably expect some trouble at the border coming back after your trip, since it will then look like you're returning shortly after having spent a long time inside Schengen, which will raise a something of a suspicion that you're intending to stay inside for such a long time again (not to mention that you won't have any balance on your 90/180 day clock). Without any documents to prove that you're entitled to do that, getting admitted will be problematic.

Most probably those problems can be resolved eventually -- if you claim to be an EEA citizen you shouldn't be sent back against your will, but will instead be detained while the authorities try to check out your story. But there's still a large chance that your day will be ruined completely along the way, and isn't it much easier simply to bring the EEA passport with you from the beginning?

(In practical terms a missing exit stamp will probably raise more eyebrows than a late one, since a late one implies that someone has already considered whether your stay was legal or not -- so what I would do in your situation would be to use the "non-EEA passports" lane the next time you leave Schengen, show both passports to the border guard and ask nicely to have an exit stamp in the non-EEA one so it matches up with the entry stamp already there).

Whenever you travel without your Schengen passport, you run the risk of being treated as someone who does not possess the right of free movement within the European union (and non-EU Schengen countries).

Nobody can predict what trouble might arise. You could be "banned" from the Schengen area if you cannot prove your Schengen nationality, though the ban would be meaningless as soon as you produce documents to prove that you are in fact a citizen of a Schengen country.

To enjoy your right of free movement, you must be able to convince the authorities that you possess the nationality of your Schengen country. The only reliable way to do that is with a passport or ID card from that country.

In other words, it is not a good idea to travel around Europe without your European passport. Whether a simple unsubstantiated "explanation" will suffice is unknowable; it depends on the official to whom you are talking, and perhaps on what kind of day the official has been having. It's pretty likely that such an official will not be pleased with having to verify your claim of European citizenship without proper documentation.