Cash payment complaint
You can notify the Tax Agency of non-compliance with the limitation on cash payments with an amount equal to or greater than 1,000 euros (10,000 if the person making the payment is a natural person who does not act as the owner of the professional company without a tax domicile in Spain).
Place and form of filing:
You can file this complaint using the form for cash payment complaints available online, with which you can provide the required supporting documentation. In the "Reporting cash payments" section, under "Procedures": Report cash payments.
You can also submit it in person at the Tax Agency's office registers.