I’m trying to build up a self employment business here but it’s hard. It’s difficult to earn enough to pay your rent food, utilities and also the 255 euros for social security +tax etc. as a self employed teacher of English. Partly because the 3 summer months I’ve no income.
So I’m still under the table after 20 months here. Spanish people in my area know I do teaching for cash in hand. So I sometimes panic and think I’m going to get done by the tax authorities ! Shit!

I’d like to know what happens if you are found out not paying autonomo? Has any poor person out there been dobbed in to authorities?

If so I’d really like to know what happened.I dont want legal trouble!

These are difficult times, prof.  I would strongly advice you to continue paying your ss contributions as a self-employed person.
There is always the possibility of an inspection.  And you don’t want to have to deal with that, do you.  Fines etc.

Maybe it’s time to think of a different career path.

Prof, nothing will happen. People don’t tell the authorities. That doesn’t mean that you should stay on the black though. What do you do for health cover? As an autonomo, you and your partner/family will be covered. How long do you want to stay here? Are pension contributions important to you? Without a declared income you cannot get credit here, if in the future you need any kind of service from your council, they will ask for your IRPF. Are you registered unemployed? There you could have a conflict.  Can’t you work part time in an English school whilst you build your private classes - they would then pay your social security, in a fully legal sense then you would have to declare the extra income in your tax return and pay the extra tax.