Why choose FacturaOk.es

1. The question you are really asking

When someone searches for “best invoicing software”, they are rarely looking for invoices. They are looking for peace of mind. The real question is one of these three:

• “Will this still work when VeriFactu becomes mandatory, or will I have to switch again in 2027?”
• “Am I going to end up with five tools and a spreadsheet gluing it all together?”
• “Will I actually understand my numbers, or just accumulate them?”

FacturaOk was built from those three questions rather than from a competitor's feature list. And all three answers are verifiable today, for free, with no card and no sales call.

2. Five reasons, in short

3. Compliance that already exists

Here is the fastest way to rule out vendors in 2026. Since 29 July 2025, invoicing software may only be sold in Spain if it complies with Royal Decree 1007/2023 and Order HAC/1177/2024, accompanied by a responsible declaration from the manufacturer stating the system's name, identifier and version.

That is not a marketing badge — it is a legal obligation on the vendor, already in force, regardless of when your own issuer obligation starts. So the question to ask any vendor is one line long:

“Show me your responsible declaration as a certified invoicing system.”

If they don't publish one, they shouldn't be selling to you. Ours is here: electronically signed with an FNMT certificate in PAdES format and validated on VALIDe, the Spanish government's signature validation service. Download it and check the signature yourself before creating an account.

And underneath that document, the parts that actually make the AEAT accept your records:

• Chained SHA-256 hash in uppercase hex, with an independent chain per taxpayer and transactional locking so simultaneous invoices never break the chain.
• Tax QR code of 30-40 mm on every invoice, with the exact legend the regulation requires, verifiable on the AEAT website.
• Cancellation records with their own hash: an issued invoice is never deleted, it is annulled and traced.
• System event log and article 16.2 flow control, honouring the AEAT's requested wait time even across deployments.
• Validation against the official XSD schemas and against the AEAT's published test vectors, inside the product's automated test suite.
• Facturae 3.2.x with XAdES signatures for FACe (public sector) and a structure ready for the B2B e-invoicing mandate of Royal Decree 238/2026.

4. Full management, not a PDF generator

Most cheap tools do one thing: turn a form into a PDF. The problem shows up three months later, when you need to know what you have spent, reconcile the bank, prepare a VAT return or justify an expense. That is when the parallel spreadsheet starts — and the parallel spreadsheet is where bookkeeping goes to die.

• Complete issuing: customers, products, series and numbering, full, simplified and corrective invoices, VAT, personal income tax withholding, equivalence surcharge, multi-currency.
• Expenses with automatic capture: upload a PDF or a photo of a receipt and the OCR extracts supplier, tax ID, base, VAT, total and category — from clean digital invoices and from crumpled paper alike.
• Bank reconciliation that matches movements against invoices and expenses, so you know what has really been paid.
• Document drive with AI classification, so files stop living in the downloads folder.
• Payments: Stripe payment links and a client portal where your customer sees and pays their invoices.
• Tax: 303 and 130 forms, issued and received invoice record books, and accounting export to A3, Sage and CSV.
• iOS and Android apps to invoice and photograph receipts on the spot.

5. AI Analyst: ask your numbers a question

This is probably the difference you feel most day to day. From the Pro plan you get a section where you type in plain language, the way you would ask an accountant: “how much did I spend on fuel in July”, “what was the largest expense this month”, “compare this quarter with the last one”.

You get the figure, the breakdown by category or month, the list of documents behind it, and a button to export everything to Excel — with native dates, currency formatting and sum formulas, not a CSV in disguise.

Now the part you should demand from anyone selling you “AI for your accounts”, because it is where most of them cheat: who computes the numbers?

6. The API your developers won't hate

If you sell online, run an ERP or have your own app, this matters more than the dashboard design. The FacturaOk REST API exists so that your system never has to learn Spanish tax law.

curl -X POST https://facturaok.es/v1/companies/$COMPANY_ID/invoices/drafts \
  -H "X-Api-Key: $FOK_API_KEY" \
  -H "X-Environment: sandbox" \
  -H "Content-Type: application/json" \
  -d '{
    "customerId": "8f14e45f-ceea-467a-9f0b-3c1f2a7d9e10",
    "paymentMethod": "transfer",
    "lines": [
      { "description": "July consulting", "quantity": 12, "unitPrice": 65.00, "taxRate": 21 }
    ]
  }'

# Issuing triggers the hash, QR, PDF, Facturae and submission.
curl -X POST https://facturaok.es/v1/companies/$COMPANY_ID/invoices/$ID/issue \
  -H "X-Api-Key: $FOK_API_KEY" -H "X-Environment: sandbox"

• Separate sandbox and production via a header (X-Environment), with fully isolated data and hash chains.
• Webhooks with automatic retries: invoice.registered, invoice.paid, invoice.annulled. If your endpoint is down, the event is retried, not lost.
• Browsable OpenAPI documentation you can generate a client from in a minute.
• API key authentication per company, revocable — no OAuth ceremony for a backend that just issues invoices.

It is the same API our own dashboard uses. There is no better internal version.

7. For accounting firms: 100 companies, one panel

If you handle invoicing for dozens of clients, issuing is not your problem — switching context without picking the wrong company is. And in 2027 your problem will be multiplying VeriFactu adoption by forty.

• Up to 100 companies in one account, switching in a click without signing in again.
• An independent hash chain per taxpayer, as the regulation requires. Mixing chains across companies invalidates the records.
• 303 and 130 forms and record books per company, ready to review and file.
• Accounting export to A3, Sage and CSV, so it fits what you already use.
• OCR and AI document classification for the invoices clients send you at eleven at night.
• One AI Analyst per company, with Excel output to attach to your report.
• Roles and permissions so each person in the firm sees only their scope.

At €39.90 a month for up to a hundred companies, that is under €0.40 per company.

8. An honest comparison

9. What it costs — and what not doing it costs

Prices exclude VAT. Paying annually saves two months. No setup fee, no onboarding cost, no lock-in — you cancel from the dashboard.

The other side of the scale is worth looking at once. Spanish Law 11/2021 introduced article 201 bis of the General Tax Act, and its amounts are not an indicative maximum — they are fixed fines. Holding non-compliant invoicing systems is penalised with €50,000 for each financial year. Manufacturing or selling them, with €150,000 for each financial year and each distinct type of system or program. Next to that, arguing about €9.90 versus €12 a month is noise.

10. What we are not

• Not a full ERP. No manufacturing, multi-site warehouses or payroll. Invoicing, expenses, payments, tax and analysis: that is what we do thoroughly.
• Not your tax adviser. We prepare forms, books and exports and give you the numbers; the filing and the tax liability stay with a professional. If you have an accountant, we work with them.
• Not the cheapest option. There are €3 tools. They have no API, no OCR, no tax forms, no analysis — and many publish no responsible declaration.
• Not a data hostage-taker. Export customers, invoices, expenses and books in open formats whenever you want, including the day you decide to leave.

11. Getting started in ten minutes

1. Create the free account — no card — and register your company with its tax ID and address.
2. Stay in sandbox for the first tests: issue two or three invoices and inspect the hash, the QR and the AEAT response.
3. Configure your series and upload your logo.
4. Upload a photographed receipt to watch the OCR work on your own real document, not a prepared demo.
5. Ask the AI Analyst something (Pro plan) and export the Excel file.
6. Move to production once you are convinced. Sandbox data stays where it is.

If step 2 doesn't convince you, you have lost ten minutes and given no card. That seems like the honest way to sell software.

This article is revised whenever the product or the regulation changes. Last reviewed: 30 July 2026.