I am doing a tax return for some extra work I did for a small business. They need the Employer' s PAYE/tax reference. I don't have this - I know I could get it by asking them.
My question is - will this small business get in trouble for not giving me any paperwork? They just asked me to give them an invoice and then put the money in my bank account. I'm not sure they are expecting me to pay tax (they paid me below minimum wage). Will there be any comeback for them in how they employed or paid me? What about national insurance?