Some invoice errors are not pricing mistakes-they start with incorrect master data. The EAN (European Article Number, 18 digits) identifies your metering point; your DSO (e.g. Fluvius in Flanders) and supplier must use the same EAN and period boundaries. Wrong EAN, wrong meter reference, or period boundaries that do not match your actual consumption window can persist for months and cause repeated overpayment or misallocated consumption. Correcting at source (and then disputing affected periods) is essential.
1. Where mismatches usually appear
- 1. A site move, meter change, or contract switch was made but the old EAN or meter ID stayed on the invoice.
- 2. Billing period boundaries overlap or have gaps between consecutive invoices, so consumption is double-counted or missing.
- 3. Meter or EAN on the invoice does not match the contract or the DSO's registration for that address.
- 4. The supplier merged several metering points (e.g. multiple EANs) into one statement with wrong allocation or one wrong EAN.
2. Diagnostic sequence that works
Validate identity first: legal entity, service address, EAN (18 digits-check against your DSO or contract), and billing period boundaries. If the EAN or period is wrong, the invoice can be internally consistent but still wrong for your site. Do not deep-dive into unit prices or indexation until the baseline (EAN, period, meter) is correct; otherwise disputes get confused and delayed.
Then quantify financial impact only for the affected periods. Avoid claiming over many months until you have confirmed the correct baseline for each period; focused, period-by-period evidence keeps the supplier response targeted and reduces the risk of blanket rejection.
3. How to recover without repeating the issue
- 1. Submit a correction request that references the exact wrong fields.
- 2. Request recalculation only after corrected identifiers are confirmed.
- 3. Add a mandatory EAN/period checkpoint to internal approval flow.
- 4. Track recurrence by supplier to detect systemic data quality gaps.
The objective is not only to correct one invoice, but to close the root cause in your control process.
4. Where to find the correct EAN and how to check it
The EAN is on your contract, on the invoice (often in the header or meter section), and in your DSO's portal-e.g. Fluvius, Sibelga, ORES, or Resa. If you have multiple metering points (e.g. multiple buildings or meters), each has its own 18-digit EAN. Ensure your internal register (sites, contracts, approval workflow) uses the same EAN as the DSO and supplier; any mismatch can lead to wrong allocation or wrong period. When in doubt, request a copy of the DSO registration for your address so you have the source of truth.
After a site move, meter change, or contract switch, confirm with both the DSO and the new supplier that the EAN and period boundaries are updated everywhere. Do not assume the supplier has the right data just because the contract was signed.
5. What to send when you open an EAN or period dispute
Send a short, factual note: incorrect field (EAN, period start/end, or meter reference), correct value with source (e.g. DSO registration or contract), affected invoice(s) and period(s), and requested resolution (correction + recalculation for affected periods). Attach proof of the correct EAN or period-e.g. screenshot from DSO portal or contract excerpt. Ask for written confirmation once the correction is applied and for a corrected invoice or credit note for the overcharged amount.
Do not bundle EAN/period disputes with pricing or indexation disputes in the same claim; keep identity corrections separate so the supplier can fix master data first, then you can address any remaining price issues in a follow-up if needed.
6. Preventing EAN and period errors from recurring
Once you have corrected an EAN or period issue with the supplier, harden your own process so it does not happen again. Add an explicit checkpoint: before any new contract or site is set up in your systems, confirm the EAN (18 digits) and the billing period logic with the DSO or supplier. When you change supplier or renew a contract, verify that the EAN and period boundaries in the new contract match what the DSO has on file. If you use an approval or ERP workflow, add a mandatory field or step: "EAN and period verified against contract/DSO (date)."
Keep a simple master list: site address, EAN, meter reference, current supplier, and contract period. Update it when you sign, switch, or correct a dispute. That list becomes your source of truth for checklist item 2 (EAN and address) and for catching mismatches before they reach the invoice.
7. When the supplier says the EAN or period is correct
If you believe the EAN or period on the invoice is wrong but the supplier insists it is correct, ask them to provide the source: the DSO registration for that address, or the meter reading dates that define the period. Compare that to your contract and to what the DSO shows you (e.g. in their portal). If the supplier's source matches your contract and the invoice, then the issue may be on your side-e.g. an outdated internal register or a mix-up between sites. If the supplier's source does not match the invoice they sent, you have a clear inconsistency to escalate.
Do not let the supplier close the case with "our system shows X" without showing you the underlying registration or reading dates. You need a verifiable baseline to know whether the invoice is right or wrong.
Final takeaway
If identity data is wrong, totals and unit prices can look internally consistent while still being wrong for your business. Treat EAN and period validation as first-line controls before approving payment.