If you're an individual taxpayer in Mexico who receives income from professional fees, rentals, or one-off invoiced work, chances are when you get paid, the deposit is smaller than the amount you agreed on. That difference is a withholding: money your client or employer hands over to the SAT (Mexico's tax authority) on your behalf.
Most people assume that money is "gone to the SAT" and that's the end of it. It isn't. That money is still yours. And if your accountant hasn't explained this to you, it's worth understanding now.
What withholding actually means
When a company pays you for a service you invoice as an individual, the law requires them to withhold a portion of your payment and remit it to the SAT under your name. It's not a punishment or an extra charge — it's a prepayment of the taxes you'll declare at year-end.
Here's a concrete example:
You invoice $10,000 pesos for a service. The company hiring you withholds:
- 10% ISR (income tax) = $1,000
- 10.67% VAT (two-thirds of 16%) = $1,067
The company deposits $7,933 to your account and sends $2,067 to the SAT in your name.
Here's the part many accountants don't explain clearly: those $2,067 belong to you. They are credited to your RFC at the SAT. When you file your own returns (monthly and annual), those $2,067 show up as a credit you apply against the taxes you owe.
How this looks in your accounting
Imagine you billed $120,000 pesos in fees over the year and your clients withheld a total of $24,800 (combined ISR and VAT withholdings).
When March or April rolls around and your accountant prepares your annual return, they'll calculate how much you owe in taxes based on your total income minus deductions. Let's say the calculation says you owe $30,000 in taxes for the year.
You won't pay $30,000. You'll pay $5,200. Why? Because the $24,800 already withheld counts as prepayment.
And if the calculation says you owe $20,000, you don't pay anything. The SAT owes you $4,800. That's the famous "saldo a favor" (credit balance) people hear about but rarely understand.
Why this matters
Once you understand that withholdings are your money, two things change:
First: you stop thinking the SAT takes from you and start thinking the SAT holds for you. Your obligation is to file, not to pay extra. Monthly and annual filings exist to reconcile what you've already paid (via withholdings) against what you actually owe.
Second: you realize your accountant needs to record every withholding correctly — otherwise you're giving money away. Every CFDI (electronic invoice) your client issues must show the withholding breakdown, and your accountant must capture it. A missing invoice means missing money.
The most common mistake
Individuals often look at their bank statement and say: "I billed $10,000 but only $7,933 hit my account — they stole $2,067 from me." Then their annual return arrives showing additional taxes owed, and it feels like double payment.
It isn't. You paid once, split across two moments: part through withholdings during the year, and part (if applicable) in your annual return. If withholdings covered enough, you owe nothing more. If they covered too much, the SAT refunds the difference.
What to ask your accountant
If your accountant hasn't walked you through this, it's not bad faith — most assume you already know. But it's worth asking for:
- A list of all withholdings made on you during the year, client by client.
- An explanation of your monthly return and where those withholdings apply.
- A heads-up at year-end about whether you have a credit balance or owe more, and how much was already covered by withholdings.
A good relationship with an accountant isn't one who says "don't worry, I handle it." It's one who explains how your own money works.
To wrap up
Withholdings are not lost taxes. They are taxes paid in advance, in your name, under your RFC. They're part of your accounting and must appear on every return you file.
Understanding this changes how you see the SAT — not as an enemy taking from you, but as what it actually is: a system that requires you to pay your taxes, but also keeps a record of every peso you've already paid.
Kiin Hub works with UC Count Riviera, an accounting firm specialized in individuals and businesses in Playa del Carmen. If you have questions about your withholdings or want to organize your accounting, we can connect you directly.
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