- Before
- Owns the outbound stream for Poland, Belgium and France and spends her mornings decoding platform codes and waiting on the ERP team. “A rejected invoice is an unpaid invoice. I want it fixed before lunch.”
- Now
- Sees every invoice of the day at its gate; opens a stop to find the cause in plain words, the corrected value with registry evidence and the Checker's verdict, and approves the change once with a reason code.
One rejected KSeF invoice, from the code to a KSeF number in 26 minutes
Kestrel & Vane Group bills from five entities in three live countries. It is Wednesday 14 October 2026, 09:40, in Wrocław. Since midnight 2,486 outbound invoices have entered the gates, and one of them, FV/2026/10/0412 for PLN 184,560.00, came back from KSeF. Here is the morning, screen by screen, in the working solution.
- 0109:40
Every invoice of the day, flowing through its country's gate
Katarzyna Nowak · AR LeadKatarzyna opens Clearance gates. Belgium 612, Poland 1,148 and France 726 invoices move left to right from the ERP, through the Validator's pre-check, through Peppol, KSeF and the approved platform, to Cleared. 2,431 of 2,486 passed first time. The 55 that stopped sit at their gate as red chips with the rule and the field, such as KSeF 450 on Buyer NIP or R0101047 on Buyer e-address, and a badge for who holds each one: the Fixer, or a person. Underneath, Germany runs as a rehearsal lane: 4,812 September invoices replayed against the 2027 rules, nothing sent.
Needs you: “FV/2026/10/0412 · rejected by KSeF. Buyer NIP not active · the Fixer is on it.”
- 0209:15 · rejected
The code, in plain words, and the agent already at work
FixerShe clicks the chip and a drawer opens beside the stream. KSeF rejected the invoice with code 450 on Podmiot2/DaneIdentyfikacyjne/NIP. The Fixer has read the response, looked up NIP 527-284-61-91 in the VAT taxpayer list — Trans-Wisła sp. z o.o., removed on 30 Sep 2026, reason: merger — and found the surviving company in REGON: Wisła Trans Logistyka sp. z o.o., NIP 521-387-44-06, an active VAT payer since 2014. Address, bank account and contact in customer master C-204118 match; only the NIP is stale.
“KSeF rejected it: the buyer’s NIP is not an active VAT taxpayer.”
- 0309:16
The evidence, and a second agent that did not see the first one's working
CheckerThe Fixer drafts the fix and regenerates the invoice: FA(3) schema valid, totals unchanged, confidence 98%. The evidence shows the master value against the registry value, with when each was read, and what else was checked: name and address match, VAT status active since 2014, bank account on the white list. Then the Checker re-validates on its own from the registries, agrees, and counts what else this record would break.
Checker: “It did not see the Fixer’s working. Same result … 14 more invoices to this customer would fail the same way · PLN 612,904.40 gross.”
- 0409:41 · decided
A person approves the master-data change, with a reason code
Katarzyna Nowak · AR LeadThe agents never change master data. Katarzyna clicks Approve the fix: the sheet shows the old and new NIP and that 15 invoices use this record — FV/2026/10/0412 is resubmitted at once and 14 more are re-queued. She picks MD-02, “Customer merged — registry evidence”, from four reason codes; a comment, if she writes one, is kept in the audit trail. The invoice is under PLN 500,000 gross, so she approves alone.
- 05Seconds later
The master is fixed once, and KSeF issues its number
FixerERP job MD-UPD-88412 updates customer master C-204118. The Fixer resubmits FV/2026/10/0412 to KSeF, signed with the company seal, and KSeF accepts it at 09:41:20 with KSeF number 5260250995-20261014-3F9A21C07B4E-8D. The UPO is stored in the archive, the 14 other invoices are re-queued with the new NIP, and the stop leaves the Poland lane: Fixed by agents goes from 38 to 39.
“Approved by Katarzyna Nowak · MD-02 · 09:41”
- 06The other fixes
Ten master-data changes, each with its registry evidence
Fixer · CheckerMaster-data fixes holds every change the Fixer has proposed to a customer or supplier record: 10 waiting, which would fix 31 invoices, with the Checker disagreeing on none. Odra Steel Components S.A. split on 1 October and invoices to the new company at 91% confidence. Scheldt Freight NV's Peppol ID 0208:0793455128 came from the company register and the network directory; its stopped invoice is €116,668.20, above €100,000, so Sofia Marchetti, Head of Tax, approves after Katarzyna.
“The Fixer proposes; the Checker re-checks; the record’s owner approves. One approval fixes every invoice that uses the record.”
- 0708:37 · inbound
Input VAT held before it is claimed, with the request already drafted
Tomasz Wójcik · AP SpecialistInbound, the Buyer agent checked all 1,904 invoices received from KSeF, Peppol and the French platform, and held the VAT on 23. FA/2026/2291 from Baltic Pallet Works sp. z o.o., PLN 61,500.00 gross with PLN 11,500.00 VAT: the supplier is an active VAT payer, the rate, order, goods receipt and duplicate checks pass, but the bank account on the invoice is not on the VAT white list for its NIP. The agent drafted the correction request; Tomasz keeps holding, sends the request or releases the VAT — each with a reason.
“The account on the invoice is not listed for this supplier’s NIP. Paying it risks joint liability for the VAT.”
- 08After the fix
A rejection becomes a new pre-check, rehearsed before anyone signs it
Fixer · Élodie Garnier, Indirect Tax ManagerToday the Validator checks only the NIP check digit before sending. After FV/2026/10/0412 the Fixer proposed checking a Polish buyer's VAT status as well, which would have stopped 6 of today's 9 KSeF rejections before they were sent. The proposal was rehearsed on 29,640 invoices from the last 30 days: 23 would have stopped, mostly buyers removed from the VAT list after a merger or a split. It goes live only when Élodie signs it.
“Waiting for your signature” · effective on signature · owner Élodie Garnier
- 091 Jan 2027 · 79 days
The next country, rehearsed on real invoices
Validator · Jonas Weber, Finance Controller, GermanyGermany requires sending from 1 January 2027. The Validator replayed September's 4,812 invoices from four German entities against the 2027 rules and sent nothing: 4,479 would pass, 93.1% against a 99.5% target held for two weeks. Three patterns explain the rest, each with an owner and a date — 212 invoices on the ZUGFeRD BASIC WL profile, 71 missing the buyer VAT ID (BT-48), 50 with payment terms as free text only (BT-20). The go-live checklist is 3 of 7 done; the last item is the Indirect Tax Manager's sign-off.
- 10Before the return
Cleared invoices tied to the VAT return, every difference explained
VAT reconciliation agent · Élodie GarnierThe VAT reconciliation agent tied September's cleared invoices to the VAT ledger. Belgium ties at €4,118,402.55. Poland's JPK_V7M differs by PLN −2,212.30: credit note KOR/2026/09/0088 was booked on 30 Sep and sent to KSeF on 1 Oct, so it stays in September's return with its KSeF number noted. France differs by €128.10, rounding on 3 invoices from one billing template. Élodie accepts each explanation, then signs the tie-out; the agent never files a return.
“VAT rounded per line in the ledger, per rate on the invoices. The invoice amounts are the legal ones.”