# FiskalAPI

> A cloud fiscal cash register (ESIR) for e-fiscalization in Serbia over a REST API. Issue fiscal receipts with a single API call, with no physical device and no monthly subscription — you pay per issued receipt only.

FiskalAPI is for anyone selling online to consumers (individuals) in Serbia who is legally required to issue a fiscal receipt: web shops (WooCommerce, Shopify, custom), SaaS and subscription services, applications, courses and digital products. It runs on the e-fiscalization model of the Tax Administration of the Republic of Serbia (an approved ESIR plus the V-PFR security element); every receipt carries a QR code and a verification link.

This is the English edition. The Serbian original is at https://fiskalapi.rs/llms.txt

## Who typically uses the English site
Development agencies and product teams outside Serbia building or maintaining software for a Serbian client or a Serbian subsidiary. Serbian fiscalization is mandatory for B2C sales, and the receipt must be issued through software approved by the Tax Administration — FiskalAPI is that approved software, exposed as a plain REST API, so a foreign team does not need to certify anything itself.

## Pricing
- API, integration and sandbox: free (no subscription, no contractual commitment).
- Billed per issued receipt only, in tiers (monthly): the first 100 receipts at 9 RSD, 101–500 at 4 RSD, 501–1,000 at 3 RSD, 1,001–5,000 at 1.5 RSD; above 5,000 by agreement. Example: 500 receipts = 2,500 RSD, 1,000 = 4,000 RSD per month.
- Settled and invoiced at the end of the month (a B2B invoice — not a fiscal receipt).
- Amounts are charged in Serbian dinars (RSD); there is no currency conversion.

## How it works
1. The client requests access and receives an API key (live plus test/sandbox).
2. That key and the public documentation are all FiskalAPI provides — no device, no installation, no subscription and no one-off setup fee.
3. The client calls the REST API from their own system; the receipt is signed with THAT client's own security element.
4. The response returns the receipt number, the QR code and the verification link, which the client forwards to the buyer.

## Key API calls
- POST /api/racuni — a sale (fiscal receipt)
- POST /api/racuni/avans — advance receipt (subscriptions, prepayments)
- POST /api/racuni/obuka — training receipt (testing the register; no tax liability and not billed)
- POST /api/racuni/refundacija — refund (referencing the original receipt)
- GET /api/racuni/{id} — read back an issued receipt, by transactionId or PFR number
- GET /api/status — taxpayer details and current tax rates
- GET /api/usage — usage and monthly cost
Authentication: Authorization: Bearer <API_KEY> (fapi_live_… or fapi_test_… for the sandbox).

## Things a foreign integrator gets wrong most often
- The tax labels (А, Ђ, Е) are CYRILLIC characters, not Latin A/E. A Latin letter is rejected with a 400. Read the labels from GET /api/status instead of typing them.
- Send your own `transactionId` on every call. It is the idempotency key; without it a repeated webhook issues a second real fiscal receipt, correctable only by a refund.
- `occurredAt` must be an absolute instant with an offset (2026-08-04T15:20:00+02:00 or …Z). A value without an offset is read as Belgrade local time.
- Billing days and months are cut at Belgrade midnight (Europe/Belgrade), not UTC.
- The `kupac.email` field is ignored by default: the seller emails the receipt to the buyer, from the seller's own domain, using the returned QR code and verification link.
- On a 502 with "statusRacuna": "nepoznato", do NOT retry automatically — the receipt may already have been issued.

## Who it is NOT for
- Selling exclusively to companies (B2B) generally does not require fiscalization in Serbia; invoices are issued instead, through the eFaktura/SEF system. FiskalAPI covers retail (B2C) fiscalization, including online sales.
- FiskalAPI covers Serbia only. It does not issue fiscal receipts for other jurisdictions.

## Links
- Site (English): https://fiskalapi.rs/en/
- API documentation (public, no account needed): https://fiskalapi.rs/en/docs/
- Accreditation (details from the Tax Administration decision, ESIR ID 1609): https://fiskalapi.rs/en/accreditation/
- Client panel ("My account"): https://fiskalapi.rs/en/account/
- Pricing: https://fiskalapi.rs/en/#cene
- Contact: https://fiskalapi.rs/en/contact/
- Serbian version of the site: https://fiskalapi.rs/