Issue and correct KSeF e-invoices

Issue an invoice for an order and send it to KSeF by hand, issue correction invoices, download the PDF and email it to the buyer.

If you sell to Polish businesses and have the KSeF add-on connected, YNS files your invoices with KSeF – the Polish national e-invoicing system – for you. Paid orders from a buyer with a tax ID are filed automatically. This page covers what you can do by hand from an order: issue the invoice when you decide, correct it later, and send it to the buyer.

Before you start: Connect the KSeF add-on in Add-ons → KSeF (environment, token and your company NIP) and turn invoices on in Settings → Invoices. See Browse and connect add-ons and Generate invoices. KSeF works for stores that sell in PLN.

Issue an invoice and send it to KSeF

Open the order. Under the order status you'll find Issue invoice – or Send invoice to KSeF if the order already has an invoice that hasn't been filed yet.

The button opens a preview of the invoice exactly as it will be filed:

• the buyer – company, name, address and tax ID
• the invoice number (or a note that it's assigned when you confirm), the issue date and the sale date
• every line with its quantity, VAT rate, and net, VAT and gross amounts, plus the totals

Check it, then click Issue and send to KSeF. YNS numbers the invoice (if it doesn't have a number yet) and sends it to KSeF.

You don't have to wait for payment. This is the way to invoice a wholesale order paid by bank transfer, for example, at the moment you choose. If the order isn't marked as paid yet, the preview reminds you – the invoice is still filed when you confirm. When the order is paid later, nothing is filed a second time.

When you can't issue it yet

The preview says what's missing and won't let you confirm until it's fixed:

If the button doesn't appear at all and you see Set up KSeF e-invoicing instead, the add-on isn't connected or is switched off.

Follow the status

The order's KSeF section shows each document and its status:

• PENDING / SUBMITTED – on its way to KSeF
• ACCEPTED – filed, with the KSeF number next to it
• REJECTED – with a short explanation and the full error underneath. Fix the cause and click Retry.

Note: Once an invoice is accepted, it's a legal document. You can't edit the order's items or addresses any more – changes go through a correction invoice or a refund.

Issue a correction invoice

When the order's invoice is accepted, the button under the order status becomes Issue correction. Use it when something changes without a refund in YNS – a price agreed with the buyer, an item returned and settled outside the store, a wrong VAT rate, or a wrong buyer address.

The form starts from the invoice as KSeF holds it now, including any earlier corrections. You can:

• change the quantity, the unit price (gross) or the VAT rate of any line
• Add line or Remove a line
• click Correct to zero to reverse the whole invoice
• tick Correct buyer details to fix the buyer's name, company or address

Enter the Reason for correction – it's required and it's printed on the correction. Below the lines you'll see the totals Before, After and the Difference (net, VAT and gross), so you know exactly what the correction changes. It can lower the amount (a credit note) or raise it.

Click Issue correction and send to KSeF. The correction gets its own number – the original number followed by /KOR/1, /KOR/2 and so on – and appears in the KSeF section with its own status.

A few rules worth knowing:

• The buyer's tax ID can't be corrected. If the NIP on the invoice was wrong, correct the invoice to zero and issue a new one.
• One correction at a time. While a correction is still on its way to KSeF, wait until it's accepted or rejected before issuing the next one.
• Each correction builds on the previous ones. The next correction always starts from the invoice as already corrected.

Download the PDF and email it to the buyer

Every accepted invoice and correction in the KSeF section has a PDF link and an Email to buyer button. The email goes to the order's customer email address, with the PDF attached and the KSeF number in the message. You can send it again whenever you need to.

Refunds and corrections

When you refund an order with an accepted e-invoice, YNS still files the correction invoice for the refund automatically.

Two exceptions:

• The order already has a correction you issued by hand. The refund may be exactly what that correction covered, so YNS doesn't file a second one on its own. The refund's correction shows as rejected with an explanation. If your correction doesn't cover the refund, click Retry to file it anyway.
• The refund can't be matched to invoice lines – a partial refund of a custom amount, or refunding "the rest of the order" after an earlier partial refund. The correction shows as rejected and points you to Issue correction, so you can say which lines changed.

See Issue refunds and handle returns for the refund itself.

FAQ

What's next

• Set up invoice numbering in Generate invoices.
• Learn how refunds work in Issue refunds and handle returns.
• Fix a buyer's details before the invoice is filed in View and manage orders.