abFaktura API

Connect your e-shop, CRM or accounting software to abFaktura. Through the API you issue invoices, record payments, download PDFs and get document changes pushed to you by webhooks.

What you need

A paid plan (Plus or Neomezeně). On the free plan the API answers 402 PlanRequired.
An API key from Settings › API keys in the app, or a program registered for OAuth 2.0.

First request

All addresses start with https://api.abfaktura.cz/api/v1. Send the key in the Authorization header:

curl https://api.abfaktura.cz/api/v1/invoices?pageSize=5 \
  -H "Authorization: Bearer abf_YOUR_KEY"

Issuing an invoice needs only the customer and the lines; abFaktura fills in the number, the dates, the supplier (your company), the bank account and the totals.

curl https://api.abfaktura.cz/api/v1/invoices \
  -H "Authorization: Bearer abf_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: order-2026-1042" \
  -d '{
    "customer": { "name": "Customer s.r.o.", "companyNumber": "12345678", "taxNumber": "CZ12345678",
                  "street": "Hlavní 1", "city": "Praha", "postalCode": "11000", "email": "billing@customer.cz" },
    "lines": [
      { "name": "Website", "quantity": 1, "unitPrice": 25000, "vatRate": 21 },
      { "name": "Hosting for a year", "quantity": 12, "unitPrice": 300, "vatRate": 21 }
    ]
  }'

The answer 201 Created holds the whole document with its number, totals and VAT summary. You can then e-mail it or download the PDF.

Basics

Format	JSON in UTF-8. Field names are camelCase, enum values are strings (`invoice`, `creditNote`, `bankTransfer`).
Dates	Dates as `2026-10-26`, times as ISO 8601 in UTC (`2026-10-26T08:30:00Z`). Days count in Czech time.
Amounts	Decimal numbers in the currency of the document, rounded to hundredths. The server always computes the totals.
Errors	`application/problem+json` with a machine-readable code, see Errors.
Limits	Plus 120 requests a minute and 20,000 a month, Neomezeně 240 and 200,000, see Limits and retries.
Version	The address holds the version `v1`. New fields may appear; breaking changes come only in a new version.

The documents follow Czech tax rules (VAT, DUZP – the date of taxable supply, credit notes). Field names are in English; Czech terms are given where they help.

Next steps

Authentication – API keys, OAuth 2.0 and permissions.
Documents – issued invoices (invoices, proformas, credit notes, quotes), received invoices, payments, PDF.
Webhooks – document changes pushed to your program.
API reference – every endpoint and schema, ready to try.