If you live in Mexico, it is a phrase you'll hear over and over again "Necesita factura o solo el ticket?" Loosely translated, they are asking if you need an official receipt or non-official receipt. Facturas are super important pieces of paper that you will be glad you saved during tax time.
WHAT IS A FACTURA?
A factura is an official receipt for goods or services that can be used for tax purposes. In order to issue a factura, the place of business must have your RFC (your Corporate tax identification number). Many people carry a laminated copy of their RFC in their wallet so it is easy to access.
CAN I USE A SIMPLE RECEIPT FOR TAXES?
No. The only document that can be used for business tax deductions is a factura.
WHAT IF I FORGOT MY RFC NUMBER BUT I NEED A FACTURA?
Many places have a window of time where you can come back with your receipt (el ticket) and present your RFC to get a factura.