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Validator

Missing P_15: total amount due in FA(3)

What this error means

The invoice has no P_15 field, the total amount due. That's the amount the customer has to pay, and it must appear on every FA(3) invoice. Without it the file doesn't conform to the schema, so KSeF (Poland's national e-invoicing system) won't accept it.

Why it's required

In its description of P_15, the Ministry of Finance's FA(3) information brochure (broszura) marks the field as mandatory. You fill in P_13_x and P_14_x only for the rates that appear on the invoice, but P_15 always.

What the field means depends on the type of invoice:

Invoice typeWhat goes in P_15
standard (VAT)the total amount due
advance (ZAL)the payment the invoice documents
final settlement (Art. 106f ust. 3 of the VAT Act)the amount still to be paid
corrective (KOR)the correction to the corrected amount
MF FA(3) information brochure, description of P_15

Our validator checks whether a P_15 element exists in Fa. The XSD schema requires it too, so the omission may appear in the list a second time, as a schema error.

How to fix it

  1. Work out the amount: the sum of all net amounts (P_13_x) and tax (P_14_x) in the summary. For an advance, final settlement or corrective invoice, use the amount from the table above.
  2. Add P_15 in Fa straight after the last P_13_x or P_14_x field, and before KursWalutyZ (if you use it) and Adnotacje. The order is fixed.
  3. Write the amount in digits, with a dot and at most two decimal places, e.g. 4920.00.
<!-- ❌ P_15 missing -->
<Fa>
  <KodWaluty>PLN</KodWaluty>
  <P_1>2026-10-08</P_1>
  <P_2>FV/10/2026</P_2>
  <P_6>2026-10-08</P_6>
  <P_13_1>4000.00</P_13_1>
  <P_14_1>920.00</P_14_1>
  <Adnotacje>...</Adnotacje>
  <RodzajFaktury>VAT</RodzajFaktury>
  ...
</Fa>
<!-- ✅ P_15 after the summary fields, before Adnotacje -->
<Fa>
  <KodWaluty>PLN</KodWaluty>
  <P_1>2026-10-08</P_1>
  <P_2>FV/10/2026</P_2>
  <P_6>2026-10-08</P_6>
  <P_13_1>4000.00</P_13_1>
  <P_14_1>920.00</P_14_1>
  <P_15>4920.00</P_15>
  <Adnotacje>...</Adnotacje>
  <RodzajFaktury>VAT</RodzajFaktury>
  ...
</Fa>

Where it usually comes from

  • A typo in the element name, such as P15 or p_15. To the validator that's a different field, so P_15 is still missing.
  • Manual editing, where the field was deleted along with the neighbouring amounts.
  • A custom export that fills in P_15 only for standard invoices and leaves it out of advance or corrective ones.

If P_15 is there but doesn't match the sum of the amounts, the validator reports a VAT calculation error. The other mandatory fields are listed in our overview of the most common FA(3) errors. Once you've fixed it, check the invoice again.

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