How to connect your business to KSeF

For Atestio to issue invoices on the taxpayer’s behalf, it needs the right permission granted in KSeF. The permission is granted once — Atestio uses it for every subsequent submission.

Prerequisites

To connect your account you need:

• Your business’s NIP — the one invoices are issued under,
• Profil Zaufany or a qualified signature — for the first sign-in to KSeF,
• access to your Atestio account with the Owner or Administrator role.

Note

If an accounting firm handles the bookkeeping, the KSeF permission is usually granted by the business owner, and the firm receives a separate permission. Both paths are described below.

Step 1 — sign in to KSeF

Signing in to the National e-Invoicing System is done with Profil Zaufany or a qualified signature, outside the Atestio platform — credentials are entered directly in the Ministry of Finance’s own system.

After choosing a method, the system asks for the NIP of the entity you are signing in on behalf of:

Step 2 — grant the permission

In the KSeF panel, grant permissions covering both issuing and receiving invoices — Atestio needs both together:

Permission	What it’s for
Issue invoices	Sending the taxpayer’s sales invoices to KSeF
Receive invoices	Pulling purchase invoices into Atestio’s inbox

Without the receive permission, Atestio will send issued invoices, but the purchase inbox will stay empty.

Step 3 — connect the account in Atestio

The connection is started in Atestio, under Settings → KSeF. Starting it redirects you to authentication; on return, Atestio confirms the permission is active.

From that point on, every issued invoice is sent to KSeF automatically.

What to do if the connection fails

“No permission” — the permission was granted for a different NIP than the one set in Atestio. Check the NIP under Settings → Business details.

Authentication ends in an error — usually because the session expired. Close the window and start the connection again.

The connection works, but the purchase inbox is empty — this means the receive permission is missing; go back to step 2.

What’s next

• Issuing your first invoice
• When to issue a correction