Why the customer files of your accounts matter
For an accounting firm, getting ready for French e-invoicing starts with the customer file of each client account: wrong or missing numbers, closed companies, VAT numbers that do not match. This page shows a before/after example, a method for ambiguous cases, and the pack built to handle several accounts.
E-invoicing is being introduced in France in stages: every company must be able to receive electronic invoices from September 2026, and issuing extends to SMEs and micro-businesses from September 2027. The official calendar is explained on impots.gouv.fr (in French). The customer's SIREN becomes an item on the invoice: see what e-invoicing changes for the SIREN.
Your clients all share the same problem: their customer file has been built over the years by hand, with numbers copied or missing. Fixing them account by account, row by row, takes time. Doing it before the first invoice avoids rejections and reminders.
Before/after example on a customer file
Four rows of a fictitious customer file, as they sit in the export from the invoicing software, then after diagnosis and correction. Names and numbers are invented.
| Customer (fictitious) | In the file | After correction | What happened |
|---|---|---|---|
| Atelier Lumière | SIREN 123 456 872 | SIREN 123 456 782 | Two digits swapped: the number did not exist, the neighbouring SIREN is suggested. |
| Garage du Port | SIREN 204 681 357 | Closed company | The number is valid but the company is closed: to be raised with the client before the invoice. |
| Boulangerie des Halles | FR40 200 000 081 in the SIREN column | SIREN 200 000 081, VAT FR62200000081 | VAT number entered instead of the SIREN, with a wrong check key: SIREN extracted, VAT number recalculated. |
| Menuiserie du Lac | No number, city: Annecy | To be identified | Row without identifier: to be matched by hand, see the method below. |
These four cases are the most common: a typo, a closed company, a VAT number in place of the SIREN, a row with no number. The first three are settled by reading the diagnosis. The fourth calls for a choice, hence the method below.
Method for ambiguous cases
When a row has no number, or the name matches several companies, do not pick at random: a wrong match is worse than an empty row, because the invoice would go to the wrong company.
- Search by name with the company search: several candidates often appear, with the same trading name or a close one.
- Add the city or postcode of the account. With equal names, the address settles most cases.
- Compare what you know about the client: activity, legal form, creation date. If a single candidate remains, note its SIREN.
- Flag to the client anything still uncertain: several candidates, a closed company, a former site. One short question is enough: "Can you confirm your SIREN?"
For a doubtful SIREN or SIRET, how to check a SIRET number and struck-off and closed companies detail the checks.
The accounting firm pack
The pack bundles 10 files for €199 excl. VAT, paid once and credited to your account, valid for 12 months. Each file can hold up to 5,000 rows. Each file includes the diagnosis, the corrected file and a PDF report to forward to your client. There is no subscription.
The diagnosis stays free and needs no account: upload a file, read the issues, then decide. The added columns are listed on the Customer file page. For an account above 5,000 rows, a single file of up to 50,000 rows exists too, and a quote is possible beyond.
The partner programme
If you recommend Jsonpage to your clients, the partner programme pays 20% of the amount excluding VAT that they pay, for 12 months. The accounting firm pack appears in the commission grid on that page. You join from a free account, with no application form and no fee.
Frequently asked questions
How much does the accounting firm pack cost?+
€199 excl. VAT for 10 files, paid once, valid for 12 months. Each file holds up to 5,000 rows and includes the diagnosis, the corrected file and the PDF report.
Can I test before buying?+
Yes. The diagnosis is free and needs no account: you see the issues in your file before paying anything.
What should I do with a row that has no SIREN?+
Search the company by name, add the city or postcode, compare the activity, and ask your client to confirm if several candidates remain.
What should I do with a closed company?+
Do not invoice without checking: ask your client whether the company changed number or whether the file is out of date.
Is there a commission for recommendations?+
The partner programme pays 20% of the amount excluding VAT paid by the clients you recommend, for 12 months.
Keep reading
- E-INVOICINGCustomer file: the errors that get an e-invoice rejectedMissing SIREN, a zero lost in a spreadsheet, a SIRET mistaken for a SIREN, a closed company, a duplicate: how to recognise them.
- E-INVOICINGFrance e-invoicing 2026: why your customers' SIREN becomes mandatoryThe four new mandatory mentions, the 2026-2027 timeline and how to verify your customers' SIREN numbers.
- SIRETHow to check a French SIRET numberThe 14-digit format, spotting typing mistakes and the difference between a valid SIRET and an active establishment.
- STATUSStruck-off, closed or dormant French company: how to tellStruck off, closed, dormant: the definitions, why to check before invoicing and how to be alerted to a change.
- APIAPI to check the SIREN and VAT numbers on your e-invoicesCheck the SIREN, SIRET and VAT number of the buyer and the seller before issuing or receiving an e-invoice: one call, examples in five languages.