Can Schengen overstay be solved by flying out of UK?

[Copykitsch]

My daughter is in Switzerland for 4 months, or so we thought. Now we know she can only stay 90 days. Her return ticket is bought. Since the UK opted out of Schengen, can she spend 90 days in Schengen, switch her return flight departure city from Zurich to London or Dublin, then fly out of the UK or Ireland without violating the rules and/or being fined? She is a U.S. citizen. I really appreciate any advice!

[steven]

If she is now in Switzerland and overstayed her visa, she might get caught upon leaving Switzerland. If she is now in the UK, and overstayed her visa in Switzerland before she traveled to the UK, she should return to the US directly from the UK. Or, she can stay in the UK long enough to be eligible to return to the Schengen zone (see the 90/180 rule).

[Copykitsch]

Thanks, Steven. She hasn't overstayed in Switzerland yet. So if she leaves Schengen before her 90 days are up, say goes to the UK, does she still have to be on her way home by the 90 day mark? Or, can she switch her flight home from Zurich to Heathrow and stay in the UK until her original fly-home date (23 days after her her Schengen 90 days would expire?)

[steven]

If she leaves Switzerland before her 90 days, and goes to the UK, then it is the same as if she went to any other country outside the Schengen zone, be it UK, USA, or Zimbabwe. UK is not part of the Schengen zone, so any time spent in the UK does not count towards the 90 days limit.