There's a lot of contradictory information out there on how to register to fly a drone in Mexico, but here's what seems to be the case in December 2023.
I will note at the outset that am filling out this paperwork and submitting it right now, so I can't say with 100% certainty that what I'm doing is going to work, but it seems pretty straightforward.
First of all, you don't need to register a sub-250g drone.
If your drone is over 250g, you do need to register it. Mexican citizenship does not appear to be required.
Here's the page on the Mexican civil aviation agency's website that deals with this: https://www.gob.mx/afac/acciones-y-programas/rpas-drones
If you are trying to do anything fancy, you'll want to check the full regulations here (backup: Google Drive link) in PDF form; here's a Google Translate translation of the form.
But if you are just a person just trying to register a reasonable-sized drone for personal purposes, it looks like all you need to do is email these documents to rpas@afac.gob.mx:
- An Excel spreadsheet (backup: Google Drive link) version of the registration form. You can go by Appendix K in the above-linked English-translation PDF to see what the blanks on the form are.
- Scanned copy of your government ID. I am going to send pictures of my driver's license and my FAA Remote Pilot license, because I am stupid proud of having a pilot's license.
- A a digitized copy of the documentation proving your ownership or possession of the drone. I'm attaching my Amazon receipt and a screenshot of my Air 3's Device Info page from dji.com.
