Staying in Spain after your legal permission to be here has run out is treated as a serious matter under Spanish immigration law, even if it doesn't feel like a criminal offense.
What counts as irregular stay
Under article 53 of the Organic Immigration Act, it is a serious infraction to be in Spanish territory without having obtained, or after the expiry of, a stay extension, residency authorisation, or similar document, when one of these is required, and you haven't applied to renew it within the deadline set by regulation. In practice, this covers people who simply never regularised their situation, and people whose permission expired more than three months ago without a renewal request.
What it can cost you
The penalty for irregular stay is a fine, set out in article 55, ranging from 501 euros up to 10,000 euros.
If your permission is close to expiring, or has already lapsed, it's worth getting advice on your options before the situation escalates.
