Monotributo 2026 Calculator + Odoo: ARCA's new categories

One-minute summary

Argentina entered 2026 with inflation cooling from a 211% year-over-year peak to 33% in February, and SMB retail up 5.6% y/y. But Monotributo — the regime that covers 1.8 million taxpayers and over 90% of registered companies — got three waves of changes in six months. Pick the wrong category and you face anywhere from AR$80,000 in retroactive recalculation to outright expulsion from the regime.

• 11 categories (A–K) capped on gross income, rent, electricity and floor space. Categories I–K are only for sale of goods.
• 3 components in the monthly fee: tax component, SIPA pension contributions, healthcare contribution.
• 2026 recategorization: January–February (wave 1) and August (wave 2). Mandatory even if your category does not change.
• CABA Unified Monotributo: live since January 2026. Pays federal monotributo + provincial gross income (CABA) in a single transaction.
• Odoo l10n_ar automates Factura C issuance and the ARCA wsfev1 webservice — but does not compute the category. You need an external calculator or custom module.
• Excel calculator at the end of the article: 11 categories, 4 parameters, both recategorization waves, threshold-proximity alerts.

What changed in Monotributo 2026

In 2025, AFIP was renamed ARCA (Agencia de Recaudación y Control Aduanero). The name changed, the resolution numbering changed (now Resolución General ARCA), and parts of the workflow shifted. But monotributo kept its underlying structure: 11 categories, 3 fee components, mandatory e-invoicing since 2015.

#1. What actually changed for 2026

• Resolución General 5616/2024 (December 18, 2024) introduced e-invoicing changes that apply from 2026 onward.
• Monotributo parameters updated January 1, 2026 — income thresholds went up roughly 14.3% versus 2025. This is not a new benefit; it is an inflation adjustment under the mobility index.
• New fee schedule from February 2026 — the usual lag between threshold updates and the new pricing.
• CABA Unified Monotributo launched in January 2026. Taxpayers domiciled in CABA can now pay monotributo and provincial gross income tax in one operation through the AGIP–ARCA API.

#2. 2026 timeline: what hits when

How the Monotributo 2026 calculator works

The math is mechanical, but ARCA looks at four parameters at once and applies the strictest. Most miscalculations come from looking at only one.

#1. The three components of the monthly fee

Each category is a fixed sum of three parts:

1. Tax component — replaces VAT and income tax. Grows non-linearly: from A to K the spread is over 100x.
2. SIPA contributions — pension. Climbs gradually from A to K.
3. Healthcare contribution (Obra Social) — identical across all categories. That is why the minimum fee in category A is not zero.

The calculator takes your inputs and returns:

• The category by the rule "does any of the four parameters land in the threshold?".
• The fee broken into the 3 components.
• An "approaching exclusion" alert when you reach 90% of the H or K cap.
• The date of the next mandatory recategorization.
• A CSV ready to import into Odoo (paying partner + category).

#2. Four parameters — all of them, not just income

ARCA checks all four at the same time. The category is set by the highest (worst-case). This is critical: many taxpayers track only billing and wake up one category higher because they forgot about rent.

1. Gross income over the last 12 months (rolling window, not calendar year).
2. Floor space dedicated to the activity (m², owned + leased).
3. Electricity consumed in the year (kWh).
4. Rent accrued in the year.

If your 12-month income lands in D but rent lands in F, your final category is F. If income is in C but annual electricity exceeds the C cap, you bump up a notch.

#3. Services vs. sale of goods

• Categories A–H — both services and sale of goods.
• Categories I, J, K — only sale of goods.

If your activity is mixed (50% services + 50% goods), ARCA treats you as a service provider — the more restrictive categorization. To reach I–K, all revenue must come from sale of goods.

Integration with Odoo l10n_ar

l10n_ar is one of the densest localization modules in Odoo. Our Odoo Argentina country pillar walks through the full setup; what follows is what the module does and does not automate for monotributo.

#1. What it covers out of the box

• Points of sale and document numbering.
• Document types: Factura A, B, C, E, MiPyMEs with CTAs, Crédito Fiscal, Nota de Crédito.
• ARCA webservices: wsfev1 (e-invoicing), wsfex (export), wsmtxca (controlled goods).
• CAE registration and status verification.
• Responsibility categories: Monotributista, Responsable Inscripto, Exento, Consumidor Final.

#2. What it does not cover out of the box

• Monotributo category computation from gross income. You need an Excel calculator or a custom module.
• Convenio Multilateral (gross income across provinces).
• Recategorization alerting — you have to set up the cron yourself.
• CABA Unified Monotributo — the API just went live in January 2026 and the l10n_ar community has not caught up.

#3. Wire calculator to Odoo in three steps

1. Paying partner of type "Monotributista" with the correct category in l10n_ar_afip_responsibility_type. Wrong type and Odoo tries to issue Factura A instead of C — ARCA rejects the CAE.
2. Point of sale of type "Factura C" — mandatory for monotributistas. Do not share a single PoS across multiple tax-responsibility types.
3. Custom "Threshold tracking" report — a simple view that sums invoices over the last 12 months and compares against the current category's cap. About 20 lines of Python in a standalone module. Without it, you only find out about a breach when ARCA sends the notice.

When the calculator works and when it does not

It works out of the box in two clean profiles:

1. Pure monotributista, single jurisdiction, services. Categories A–H, one Factura C PoS in Odoo, l10n_ar + Excel calculator + monthly review. Covers about 80% of SMBs.
2. Retail seller, categories G–K, single province. Calculator by income + electricity and floor-space tracking. Odoo's POS module aggregates invoices automatically.

It needs customization for:

3. Mixed services + goods operations. The calculator must apply the stricter rule (services), but many off-the-shelf templates skip it. The error runs between AR$50,000 and AR$200,000 in retroactive recalculation.
4. Convenio Multilateral (gross income across 2+ provinces). ARCA monotributo is not integrated with provincial jurisdictions. You need a separate module to track IIBB per province and file CM-05 forms manually.
5. CABA Unified Monotributo. Launched January 2026 in public beta. l10n_ar has not been updated for unification — manual entry in the AGIP/ARCA portal only.

And it does not cover at all:

6. Professional on monotributo plus employment. If you are on monotributo as a freelancer and work as an employee, part of your SIPA contributions is already paid by the employer. Standard calculators ignore this; the accountant handles it individually on form F-184.

5 common mistakes

1. Computing the category by billing alone. The most common error. ARCA checks four parameters; busting the rent cap means an automatic category jump. Verify annual rent before locking the category.
2. Issuing Factura A or B instead of C. Monotributistas can only issue Factura C. If a Factura A slips through with CAE, that is a regulator failure and ARCA will reverse it eventually. Recovery is nearly impossible.
3. Ignoring exempt income. Investment returns and interest are exempt from tax — but they count toward gross income for categorization. People miss this constantly.
4. Skipping recategorization "because I did not grow". Recategorization is mandatory every six months whether you moved or not. Skipping it costs AR$1,500–50,000 depending on category and delay.
5. Using last year's Excel calculator. Thresholds change twice a year. A 2025 template is calculating on stale parameters. Use a template with a visible last_updated date and subscribe to updates.

Anonymous case: marketing agency in Buenos Aires

Situation: performance marketing agency, 4 people, monotributista category G on 2025 billing. In April 2026 trailing-12-month income approached the G cap. The accountant said: "either trim Q3–Q4 invoicing, or move to H before August".

What they did:

1. Activated a monthly threshold-tracking view in Odoo — got the trajectory and year-end projection.
2. Built an Excel calculator with two scenarios: "stay in G" (cut Q3–Q4 invoices by about 12%) or "move to H" (fee goes up around 38%, healthcare contribution unchanged, new rent cap).
3. Decided to move to H in the August wave. That kept client work intact and let them sign new contracts before year-end.

Outcome: August recategorization passed without surprises. Q3 profit landed 18% above the "stay in G" scenario. The calculator saved one extra meeting with the accountant (USD 150–250) and prevented an automatic ARCA recalculation with interest (~AR$80,000 under article 38 of the monotributo RG).

The expensive part is not the higher fee — it is finding out late that you already crossed the threshold.

Download the Monotributo 2026 Excel calculator

The template covers: 11 categories A–K, the 4 categorization parameters, both 2026 recategorization waves (January and August), threshold-proximity alerts, the 3-component fee breakdown, and a CSV ready to import into Odoo l10n_ar. Updated with each new ARCA Resolución General.

Once calculator and Odoo are tuned, the next steps are: provincial gross income monitoring (if you sit under Convenio Multilateral), threshold tracking as a cron job inside Odoo, and a quarterly review with your accountant on Odoo analytics. Getting monotributo wrong is easy; the cost of recovery is low — if you catch it in time.

Related guides:

• Odoo in Argentina: l10n_ar for SMBs — country pillar with partner directory and pricing.
• AFIP/ARCA and Odoo in Argentina — regulatory context for the AFIP→ARCA switch.
• 30-minute Odoo audit — no-commitment diagnosis.

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