Overview
The four VAT rates Notaly's e-invoicing API accepts are 23%, 8%, 5% and 0%, one rate per invoice line. The 7% rate, exemptions (zw) and reverse charge (odwrotne obciążenie, oo) are not supported today, so a line using one of them fails Notaly's validation with a 422 before it reaches KSeF.
The four supported rates
23% is the standard rate. 8% and 5% are reduced rates that apply to specific categories defined in Polish VAT law. 0% covers the zero-rated domestic supply (0 KR). Export (EX) and intra-community supply of goods (WDT) are not currently supported: the API always sends 0% as 0 KR, so do not use it for those supplies. Notaly checks that the code you send is one of these four; it does not decide which rate is legally correct for your supply.
What the FA(3) schema supports vs what Notaly accepts
The FA(3) schema itself is richer than four rates: it can carry GTU codes, procedure markings and other P_12 values such as 0 WDT and 0 EX. Notaly's generator currently accepts the four numeric rates and does not yet model GTU, procedures or the zw/oo markings. If your invoices need those, that data would have to be handled outside the API until Notaly adds it.
What happens with an unsupported rate
Send vatRate: 7 or a zw/oo marker and the API answers 422 validation_failed with a details list. This is Notaly's own validation, not a KSeF rejection — the invoice never leaves your account, so it does not consume a sandbox test invoice. Fix the rate or handle the case outside the API before you rely on it in production.
Confirm the rate, not just the code
The rate you put on the invoice must match what Polish VAT law requires for that supply. Notaly verifies the code is one it accepts; it does not calculate taxes or choose the correct rate. Confirm the applicable rate for your goods or services with your accountant.
FAQ
Which VAT rates does Notaly accept? 23%, 8%, 5% and 0%, one rate per invoice line.
What happens if I send 7%, zw or oo? The line fails Notaly's own validation with a 422 before it reaches KSeF, so the invoice is not sent.
Disclaimer
Notaly is not a tax, accounting or legal advisor. This article is general information, not tax advice, and may be outdated. You are responsible for your own VAT compliance; confirm with a qualified accountant where required.
Sources
Source: www.podatki.gov.pl