Automate AFIP (ARCA) E-Invoicing: Step-by-Step 2026 Guide

If someone at your company logs into the ARCA portal every day to type out invoices that already exist in another system, you're paying twice for the same data. Automating invoicing with AFIP (now ARCA) means your management system issues the documents on its own, via the official web services: it requests the CAE, generates the PDF and sends it to the customer with no human intervention. It's one of the highest-return integrations available in Argentina: the process is 100% automatable end to end, and the agency has officially supported it for more than a decade.

What you can automate with ARCA's web services

ARCA exposes several services, but for invoicing these are the ones that matter:

• Document issuance (WSFE / wsfev1): A, B and C invoices, credit and debit notes. Your system builds the document, sends it and receives the CAE (Electronic Authorization Code) with its expiration date. No CAE means no valid invoice.
• Export invoices (WSFEX): if you sell services or products abroad.
• Taxpayer registry lookup (ws_sr_padron_a5 / a13): with the customer's tax ID (CUIT) you get the legal name, address and VAT status. This eliminates the classic "can you send me your billing details?" and the data-entry errors that come with it.
• Document verification (WSCDC): confirm that the invoices your suppliers issue to you are valid, useful for automating purchasing.
• Received online documents: through "Mis Comprobantes" you can reconcile what was invoiced to you against what you recorded — we cover this in detail in the guide on automation for accounting firms.

In practice, a complete automated flow looks like this: a sale is confirmed in your system (or on MercadoLibre, or in your online store) → your backend validates the CUIT against the registry → it issues the document via WSFE → it receives the CAE → it generates the PDF with the regulatory QR code → it sends it by email or WhatsApp to the customer → it records everything in your accounting. Total time: 2 to 5 seconds.

Requirements: what ARCA asks for before your first automatic invoice

This is where most people get stuck, so let's go in order:

1. Digital certificate. You generate a key pair (with OpenSSL or similar), upload the certificate request (CSR) from the ARCA portal with a level-3 tax PIN, and the agency returns an X.509 certificate. That certificate is what your system uses to authenticate against WSAA (the authentication service) and obtain access tickets that last 12 hours.
2. Associate the certificate with the service. From "Administrador de Relaciones de Clave Fiscal" you have to authorize the certificate to use "Electronic Invoicing".
3. A Web Services point of sale. Portal points of sale don't work for the API: you have to register a new one with "Web Services" mode. The document numbers for that point of sale are managed by your system (querying the last authorized number so you don't fall out of sync).
4. Homologation first. ARCA has a testing environment with its own certificates. Every serious integration is tested there before touching production: documents rejected in production are an accounting headache.

None of this requires in-person paperwork, but it does require technical precision: WSAA uses SOAP with messages signed using CMS, a standard with its own quirks. It's typical work for an API and integrations development team.

Direct integration vs intermediary API: the key decision

Talking directly to ARCA isn't always the right call. There are intermediary services —TusFacturas, Facturante, AfipSDK, among others— that expose a modern REST API and handle the SOAP, the certificates and the regulatory changes for you.

Criterion	Direct integration (WSFE)	Intermediary API
Upfront cost	USD 1,500-4,000 in development	USD 0-300 in setup
Monthly cost	~0 (runs on your server)	USD 15-60/month + document cap
Cost at scale (5,000 invoices/month)	No change	Higher-tier plans or per-document cost
Implementation time	2-4 weeks	2-5 days
Third-party dependency	ARCA only	ARCA + the intermediary
Regulatory changes	You maintain them (or your partner)	Absorbed by the provider
Billing data	Stays in your infrastructure	Passes through the third party

The practical rule we use with clients: fewer than 500 documents per month and a need to launch now → intermediary. More than 1,000 monthly documents, sensitive data or a robust in-house system → direct integration, which pays for itself in the first year and doesn't tie you to anyone's pricing.

Want to know which integration fits your invoicing volume? Book a 30-minute call and we'll put together the diagnosis at no cost.

Step by step of a direct WSFE integration

In short, the path we walk through on every project:

1. Certificate generation and homologation registration (1-2 days, including the tax-PIN bureaucracy).
2. WSAA authentication layer: CMS signing of the access ticket, caching the token for 12 hours, automatic renewal.
3. WSFE client: building the document (type, concept, VAT rates, recipient's tax status), requesting the CAE, handling ARCA's errors and observations.
4. Last authorized document lookup: to keep numbering in sync even if there were manual issuances.
5. Credit and debit notes linked to the original document (referencing is mandatory).
6. PDF generation with QR code per the current resolution, and automatic delivery to the customer.
7. Retries and queueing: ARCA's web services go down often, especially at month-end. A professional integration queues the documents and retries instead of failing the sale. This point separates a toy integration from a production one — the pattern is the same one we explain in what an API is and how it integrates systems.
8. Go live with the real certificate and monitoring.

If your management system is old or closed and has nothing to trigger issuance from, all is not lost: there are ways to connect legacy systems without an API.

Real costs in 2026

Conservative numbers for LATAM:

• Intermediary API: USD 15-60/month depending on volume, plus the day or two of integration on your side.
• Custom direct integration: USD 1,500-4,000 one-time for issuance + CAE + credit notes + registry lookup. If you also have to touch your management system to trigger invoicing from sales, the full project usually runs between USD 3,000 and 8,000.
• Typical savings: a company that issues 800 invoices/month by hand spends between 25 and 40 admin hours a month on that alone. At 2026 Argentine labor costs, the direct integration pays for itself in 4 to 8 months, not counting the typing errors that disappear.

And outside Argentina? SII, DIAN and SUNAT

If you operate in several countries, the good news is that the architecture repeats:

• Chile (SII): the DTEs (Electronic Tax Documents) are issued as signed XML against the SII's web services, with a digital certificate and a prior certification process.
• Colombia (DIAN): electronic invoice in UBL 2.1 format, validated in advance by the DIAN, generally through authorized technology providers.
• Peru (SUNAT): the CPEs (Electronic Payment Documents) are issued via SUNAT's services or through an OSE (Electronic Services Operator).

A well-designed system abstracts the "tax issuer" behind a single interface: the business logic doesn't know whether it's invoicing against ARCA, the SII or the DIAN. That's exactly what we build when a client invoices in more than one country with custom software.

When you should NOT automate invoicing

Honesty first:

• You issue fewer than 50 documents per month: the ARCA portal or the mobile invoicer are enough. The savings don't justify even the cheapest intermediary plan.
• Your sales process is still chaotic: if the sales data isn't in any system (everything by WhatsApp and memory), get the operation in order first. Automating on top of nonexistent data doesn't generate invoices, it generates problems.
• You're about to switch management systems: integrate after migrating, not before, or you'll pay for the integration twice.

Start with the invoice, continue with the rest

Automatic invoicing tends to be the entry point: once the document goes out on its own, the natural next step is to automate collections, reconciliation and reminders — the full ecosystem we describe in what programmatic automation is.

At Deepyze we've built ARCA integrations for distributors, ecommerce and service companies in Argentina, plus their equivalents for Chile and Colombia. We work with fixed pricing, a concrete proposal in 24 hours and a team in your own time zone that understands what a rejected CAE on the 31st at 11:50 PM means. Tell us about your case and we'll tell you exactly which integration you need and what it costs.