What the automation does

Every month the accountant needs a package of that month’s tax documents: the invoices (CFDIs), the bank’s monthly statement, and anything else that belongs to the month. This automation builds that package from a folder in Dropbox and emails it to the accountant for you, as a reply on their own monthly request email.

It runs in the cloud on a schedule. Nothing needs to be switched on at home, and there is no app to open. Your side of it is one habit: keep the month’s documents in the month’s Dropbox folder. The automation does the rest and keeps you informed by email.

Every email it sends you has a subject starting with [Impuestos MX], so they are easy to spot and easy to search for.

The one folder that matters

Inside the taxes folder in Dropbox, each month has its own folder named by month and year in the form MM-YYYY — for example 07-2026 for July 2026. The month folder can sit at the top of the taxes folder, or inside a year folder (like 2026/07-2026); the automation finds it either way, so tidying folders into years later is harmless.

Only files directly inside the month folder are packaged. Anything in a subfolder is left alone on purpose, and zip files are never included.

How a normal month plays out

1. During the first days of the month, the automation checks the previous month’s folder every hour. It opens each new PDF and reads its contents, looking for the bank’s monthly statement (the estado de cuenta) for that month. Because it reads the contents, the file’s name does not matter — save the statement under any name.
2. The moment the statement appears, you get an email listing everything that will go in the package and the exact time it will be sent — 12 hours later. That 12-hour window is your chance to add a missing file, or to stop the send (see the Controls page).
3. 12 hours later, the package goes out: a zip of the folder plus a one-page summary PDF (Resumen MM-YYYY.pdf) listing every document. It is sent as a reply-all on the accountant’s own request thread for that month, so it lands where they expect it. You get a confirmation email showing exactly who it went to and what it said.
4. Done. For the rest of the month the automation only watches for stragglers: if a new file appears in the folder after the send, it emails you about it and sends nothing further on its own.

So in the normal case, your whole month is: drop the statement (and any invoices) into the folder, read two emails.

What you do each month

1. Save the month’s invoices and documents into the month’s Dropbox folder as they arrive.
2. When the bank’s monthly statement becomes available (usually in the first days of the following month), download it and save it into that same folder.
3. When the “listo — se envía…” email arrives, glance at the file list. If something is missing, add it to the folder within the 12-hour window.
4. When the confirmation email arrives, you’re done for the month.

If the statement is late

The accountant’s deadline is the 9th, and the automation protects it:

• On the 7th, if no statement has appeared yet, it emails you a reminder.
• On the 8th, if there is still no statement, it packages whatever is in the folder and sends that (after the same 12-hour hold), with a line telling the accountant the statement will follow separately. When the statement does arrive, you forward it yourself on the same email thread.

If the statement turns up during that 12-hour hold, it simply rides along in the package and the “will follow” line is dropped.

It never sends twice

The automation keeps a small hidden record inside each month folder of what it has checked and sent. Re-runs are always safe: a month that has been sent stays sent, no matter how many times the schedule fires.