1. What a "pago a cuenta" is (and why it isn't the final tax)
Every month, if you're under RMT or Régimen General, you file a pago a cuenta of the Impuesto a la Renta de Tercera Categoría together with the IGV. It's a prepayment toward the annual tax, which only gets finally calculated in the Declaración Jurada Anual — on its own, it isn't "the tax for the month."
2. The coeficiente: calculated from your own track record
The coeficiente comes from dividing the prior year's calculated tax by that same year's net income. That number (with several decimal places) gets applied to each month's net income in the current year to work out how much to pay as a pago a cuenta.
Because it depends on a full prior fiscal year, a newly formed company — or one that had a loss the year before — has no coeficiente to calculate: it uses the other method in the meantime.
3. The 1.5%: the floor when there's no coeficiente (or for comparison)
The second method is simply 1.5% of the month's net income, with no dependence on any track record. Régimen General and RMT (once it exceeds the annual income cap for the reduced rate) must calculate both methods every month and pay whichever is higher — you don't get to pick whichever is more convenient, you compare and pay the higher one.
4. Which one applies to your regime
- RMT, as long as your annual net income doesn't exceed 300 UIT: you pay 1% of the month's net income, without comparing coeficiente or 1.5%.
- RMT, if you exceed 300 UIT a year, or Régimen General: coeficiente vs. 1.5% gets compared every month, and you pay the higher one.
- RER doesn't enter into this comparison — it pays 1.5% of its monthly net income directly, as a single, final Renta rate, with no annual return with adjustments (see our article on tax regimes).
5. When you can suspend or adjust your pagos a cuenta
If your profit margin for the year drops significantly compared to the one that produced your coeficiente, you don't have to keep paying as though nothing had changed. There are procedures — available starting in certain months of the fiscal year — to suspend or adjust your pagos a cuenta, supporting the request with an income statement that reflects the real drop in your margin. It isn't automatic: you have to file for it and support it, not just stop paying.
6. What happens to the difference at year-end
The Declaración Jurada Anual calculates the year's actual tax, and every pago a cuenta made month by month gets subtracted from it. If you overpaid during the year, you get a saldo a favor that you can carry forward or request as a refund, as applicable. If you underpaid, you have to pay the difference — the regularización — together with the annual return.
7. How factsimil handles it
Since each month's net income comes directly from the facturas and boletas already issued in factsimil, the Financial Reports module shows the base used to calculate each month's pago a cuenta without having to gather it by hand. If you keep full accounting, that same figure is reflected in the Libro Diario.
Check the details in the Accounting plan, or create a free account to try it.