What follows are the details of everything I had to do to obtain FM-3 work permit documentation in Mexico, after having applied for and received authorization.
-A: I went back to Migración and got another list of requirements to get the actual visa document. This included a very specific headshot from more than one angle that they will do at most photo studios and a lot of “document” shops. Don’t do it yourself. It cost me 80 pesos. You also have to fill out some more forms, including a near-duplicate form of one you already filled out to initiate the paperwork. It’s a trámite form, sort of like a coversheet. Of course there was another fee as well, the fee for the actual green FM-3 booklet, of about 2000 pesos, for which I had to obtain another clave and go back to the bank.
The other form I had to fill out was the FM-3 application, which they told me I needed to fill out “por máquina.” Typed only, in other words, no pens. I asked if I could use the PDF on their website and they told me no, but I did it anyway. It was only slightly different from the one they gave me in hard copy and I’d be damned if I was going to pay some guy to sit there and fill it out for me on a typewriter or in a PDF on his own computer. The form also has spaces for the photos and for fingerprints, but Migración will take care of affixing the photos and take your fingerprints there in the office.
-B: So I brought all the paperwork back in. I had to get my payment receipt verified this time at a special desk at the immigration office. Then I turned it all in, and they accepted everything, including my website PDF. They gave me a date to come back to pick up my actual FM-3, about 3 more weeks later. That day I returned they had affixed the photos into the booklet. They had me sign inside it and took my thumbprint.
-C: Despite the police-iness of all the info they ask for (including info about the size of your nose and mouth, and descriptions of scars, tattoos, etc), none of this process involves the next step, which is getting yourself registered as a foreigner, in the Régistro Nacional de Extranjeros, a separate agency. No one pointed out the blank space for this registration in my FM-3, so I assumed my FM-3 was done.
-D: I did not find out about the Register of Extranjeros until I got to my appointment with the taxman to get a taxpayer number, for which I had waited a month. The woman there told me she couldn’t register me as a taxpayer until I had those empty spaces in my FM-3 filled. She told me to go back to immigration for it. I am prone to serious anxiety when told no by bureaucrats and had to blink back tears. I asked her if she thought it was something Migración had simply forgotten or what. Although she was sympathetic, she didn’t know.
-E: I went back to immigration. They told me about the National Registry of Foreigners to fill in those numbers missing from my FM-3, which are called a CURP (Clave Único de Régistro de Población).
For an overall view of getting permission to work freelance and paying taxes in Mexico, see the complete list of steps I took to make myself legal.