Shop for goods that are worth at least 1200 pesos at participating stores. Individual goods may cost less but the total purchases should amount to 1200 pesos. Credit card purchases should only be done by Visa card, American Express and Mastercard express credit cards.
Leave Mexico by air or sea through any airport and cruise ship terminal.
Note: stores participating in the tax refund scheme have a money-back logo.
How to claim your VAT refund
Present your passport, immigration form( FMM)and purchase receipts to the money-back office at the airport or cruise terminal you're departing from. If you depart Mexico by land you're not eligible for tax refunds.
I was asked to also present the goods I bought, apparently, goods being shipped out of Mexico don't qualify for tax refunds, only goods that are part of your luggage qualify for tax refunds.
Takes about a month or two for money back to credit your tax refund to your in your local currency.