Anyone billing in Spanish to clients across several countries eventually runs into this conversation: «in Argentina I’d pay monotributo,» «in Mexico that’d be RESICO,» «here in Spain it’s just autónomo.» These are three regimes that exist to solve the same thing — so someone working for themselves with moderate income doesn’t have to run the accounting of a mid-sized company — but they resemble each other far less than the quick bar-table comparison suggests.
Monotributo (Argentina): brackets, not a percentage
Monotributo isn’t a percentage of your income — it’s a fixed monthly fee depending on which bracket (A through K) you fall into based on annual turnover. In 2026, bracket A covers up to around 12 million pesos a year in turnover, and K — the highest within the regime — up to about 126.6 million. Exceeding your bracket’s limit forces a recategorisation; exceeding the maximum limit removes you from monotributo entirely and moves you to the general regime.
For those exporting services (billing clients outside Argentina), monotributo remains valid, with the particularity that you must issue an «E» invoice and that income still counts toward your bracket limit, on top of being subject to the currency-control rules on foreign-currency collections — the part that causes the most practical headaches, more than the tax side itself.
RESICO (Mexico): the simplest of the three, with a lower ceiling
Mexico’s Simplified Trust Regime applies to individuals with annual income up to 3,500,000 Mexican pesos. The mechanics are the simplest of the three regimes compared here: income tax (ISR) rates ranging from 1% to 2.5% on income actually collected, without the general regime’s complex deductions, explicitly designed to cut the administrative burden for people working on fees or individual business activity.
The condition most people miss: you can’t be in RESICO if you’re a partner or shareholder in a company related to your activity, or if your income is treated as salary (for example, as a board member or director). It’s a regime for genuine freelancers, not for someone billing through a corporate structure.
Autónomo (Spain): the priciest fixed cost at the bottom, and the only one with no ceiling
Unlike the other two, Spain’s self-employed system has no upper turnover limit that pushes you out of the regime — you move up income-tax brackets, but you stay autónomo. Its distinguishing feature versus monotributo and RESICO is the social security contribution (RETA), paid from the very first euro of activity regardless of how much you actually bill, with brackets that have been rising steadily in recent years. For someone billing little or irregularly, it’s structurally the most expensive of the three in the early stage; for someone billing a lot, it’s the only one that doesn’t force a change of regime or legal structure as you grow.
The comparison that actually matters
| Monotributo (AR) | RESICO (MX) | Autónomo (ES) | |
|---|---|---|---|
| Structure | Fixed fee by bracket | % of income collected (1-2.5%) | Progressive income tax + fixed social security fee |
| Income cap | Yes, by bracket (up to ~126.6M ARS/year in 2026) | Yes, 3,500,000 MXN/year | No ceiling |
| Cost at low income | Low, tiered | Very low | High relative to income (fixed contribution) |
| Exporting services | Allowed, with «E» invoice and currency controls | Allowed like any other income | Common, under intra-EU/export VAT rules |
In the comments: if you bill from Argentina or Mexico to European clients (or the other way round), share how currency controls, double taxation, or simply the bank’s paperwork affect you in practice when collecting in another currency. That real-world friction never shows up in comparison tables.
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Sources: monotributo bracket tables in force at ARCA (formerly AFIP) for August 2025-January 2026, RESICO tax guides updated for 2026 (SAT, Fiscaly, Alegra), Spanish self-employed contribution regulations (RETA). This isn’t tax advice — each regime has exceptions and edge cases worth checking with a local accountant.