As an expat freelancer, I suggest to get an accountant from the start, to help set up the business but also to run it. What accountants usually don’t help with, is how you safe your money for tax payments.
In Spain, you usually pay two different taxes: IRPF (income tax) and IVA (VAT). IRPF is 19% right now and IVA 21%. The calculation is a bit tricky. Let’s assume you invoice your client in Spain 1000 EUR (IVA and IRPF only apply for national invoices): > Invoice for my services: **1000 EUR IRPF Tax (-19%): -190 EUR **IVA (+21%): 210 EUR > Total: 1020 EUR … »