Factura (CFDI) (Official Tax Invoice)fak-TOO-rah
A factura is a digital tax invoice (Comprobante Fiscal Digital por Internet, or CFDI) required by Mexico's tax authority SAT to document all taxable transactions, including property purchases, rentals and construction expenses. The current CFDI 4.0 format is governed by Federal Tax Code Articles 29 and 29-A.
By Daniel Ortega · Last reviewed 11 November 2026
How it works
<p>When a foreign buyer purchases property in Mexico, the seller must issue a CFDI in XML format to the buyer at the time of sale. The buyer needs an active RFC (Mexican tax ID) to receive a valid CFDI; if the buyer does not provide an RFC, the generic RFC XAXX010101000 may be used, though such general-public invoices are not deductible or creditable. The notary or attorney can help obtain a personal RFC before closing. The CFDI is validated in real time by SAT through an authorized certification provider (PAC), stamped with a unique digital tax stamp (Timbre Fiscal Digital) and assigned a UUID (folio fiscal). For real-estate transactions, the CFDI includes the property tax account number (cuenta predial). The factura is critical for tax purposes: only expenses backed by a valid CFDI tied to the buyer's RFC are deductible against capital gains when the property is later sold. Under ISR Law Article 121, if a buyer cannot prove the purchase cost with a CFDI, SAT limits the deductible cost basis to 10 percent of the future sale price, dramatically increasing the taxable gain and the ISR owed. The buyer should keep both the XML file and the PDF representation permanently.</p>