API pricing & limits

The public API and the MCP server are included in every paid Factuarea plan. There is no add-on to buy and no access request: create a key from Dashboard → Developers → API Keys and start calling /v1.

Capacity is part of the plan as well: there is no separately purchasable Developer API tier or boost. Changing plan changes the effective tier for all existing keys automatically.

Tiers

Figures for Free, Starter and Pro measured in the backend tier configuration source on 2026-10-01. For how the quotas behave — sliding window, X-RateLimit-* headers, the company and account-portfolio aggregate axes, 429 codes and the back-off strategy — see Rate limits.

An account that holds two or more real tax IDs also has a portfolio: its requests are counted together, whichever tax ID they reach. The portfolio ceilings are flat per tier, so adding tax IDs does not raise them, and the per-minute and monthly ones only observe for now. What each additional tax ID costs is in Additional tax IDs.

What your plan already grants

The tier follows the plan on its own: it is not chosen per key or per request, and it changes as soon as your plan does. A historical grandfathered_addon migration may preserve a higher tier while an eligible plan remains active; legacy boosts that were not migrated are inert.

Caps that are not requests

Two limits are counted per company rather than per request.

Active API keys

A key counts while it is neither revoked nor expired; revoking one frees a slot immediately. Creating one past the cap responds 422 with code: max_api_keys_exceeded, naming the tier and the cap. To get past it, revoke a key you no longer use or move to a plan with a higher tier.

The cap in the table is counted per tax ID. An account that holds two or more real tax IDs also has a cap for the whole account, portfolio_max_api_keys: 1 in Free, 15 in Starter, 500 in Pro and 2,000 in Scale. It counts every key of the account that is not revoked, test keys included, comes on top of the per-tax-ID cap and responds 422 with code: portfolio_max_api_keys_exceeded. A single tax ID and its sandbox only meet the per-tax-ID cap, and adding tax IDs does not raise the account cap. See Rate limits.

Webhook endpoints

An endpoint counts while it is live (active or degraded); a disabled or deleted endpoint does not. Creating one past the cap responds 422 with code: business_rule_violation and subcode: max_webhook_endpoints_reached.

Test mode is not a cheaper tier

A fact_test_ key carries the same tier as your live keys, so the same per-key minute and monthly quotas apply to sandbox traffic. The aggregate company and account-portfolio axes bypass sandbox companies: test traffic does not consume the live company's aggregate capacity.

What the sandbox removes is the real-world effect, not the quota: VeriFactu records are created locally and never transmitted to the AEAT, document emails are not delivered to real recipients, and events are recorded but not delivered to your endpoints. See Test mode & sandbox for the full list.

One cap does behave differently: test keys live in a separate sandbox company, so they count against that company's own key allowance instead of your live one.

High volume

Scale has no published price. Request capacity, active API keys and webhook endpoints are agreed in the Enterprise contract. Write to info@factuarea.com from the email associated with your company in Factuarea, with the request volume you expect and the endpoints you will hit if you need an audited company-specific increase. Scale also carries a service-level agreement and a dedicated account manager.

Checking what you consume

Dashboard → Developers → Usage shows your consumption against the current tier. Every API response also carries the X-RateLimit-* headers, which is the cheapest way to spot that you are approaching the limit before you hit it — see Rate limits for how to read them.