Guide
Bank details, social security numbers and company numbers sit in payslips, statements and invoices. Each says more than it seems, and each has a check digit that helps find it.
Updated
| Number | Shape | What it says | Check |
|---|---|---|---|
| IBAN | FR76 then 23 characters for a French account (27 in all) | The bank, the branch and the account; enough to set up a direct debit | MOD-97 on the whole number |
| BIC | 8 or 11 letters and digits | The bank and its country | Structure only |
| NIR (social security number) | 13 digits and a 2-digit key | Sex, year and month of birth, department and town of birth | Key: 97 minus the number modulo 97; 2A and 2B for Corsica |
| SIREN | 9 digits | The company, or the sole trader behind it | Luhn |
| SIRET | 14 digits: the SIREN and a 5-digit establishment number | One establishment of the company | Luhn, with one documented exception |
The same number often appears several times in one file, in different forms:
Mask a number whenever the recipient does not need it. A landlord needs proof of income, not the NIR on the payslip; an expert needs the amounts of a statement, not the IBAN; a court exhibit rarely needs the account details of a third party.
Keep it when it is the point: the IBAN on bank details sent to be paid, the SIRET of a supplier on a public invoice. The SIREN or SIRET of a company is public information; that of a sole trader identifies a person, and deserves the same care as a name.
Searching a PDF for a number finds it only if it is written exactly the same way. FR76 3000 6000 0112 3456 7890 189 and FR7630006000011234567890189 are the same IBAN; a NIR can be split across two lines or two table cells; a scanned page has no searchable text until it is read by OCR.
Check digits solve the opposite problem: a sequence of 13 digits is not necessarily a NIR. A tool that checks the key tells a real number from a phone number or an order reference, and avoids masking what should stay.
Obscelis looks for these numbers with bounded patterns, then validates each candidate: MOD-97 for the IBAN, the control key for the NIR, Corsican 2A and 2B included, Luhn for the SIREN, the SIRET and payment cards. A nearby label ("IBAN", "N° de sécurité sociale", "SIRET") raises the confidence; a pattern alone never gets high confidence for a number with a key.
Scanned pages are read with OCR first, and forms with one digit per box are read box by box. You accept or reject each finding, apply a decision to every occurrence of the same number in one go, and add your own identifiers, such as client or file references, in Settings.
An IBAN is meant to be shared to receive payments, but it is also what a direct debit needs. Send it when someone has to pay you; mask it on documents sent for another reason, such as statements attached to a rental application.
Some organisations mask all but the last few digits so that the number can still be recognised. Decide what the recipient needs; the safest default is to mask the whole number.
IBANs from every country that uses them are validated with their own length. The NIR, SIREN and SIRET are French; for other identifiers, you can define your own rules.
Redacting a PDF means removing information from the file, not hiding it on screen. Here is the method, the traps, and how to check the result.
Reading an application without the name, the photo or the address keeps attention on experience and skills. Here is what to mask, what to keep and how to organise it.
Drawing a black rectangle over a name hides it on screen, and nowhere else. The text stays in the file, one copy and paste away.
Download it for macOS, Windows or Linux: the trial needs no account and no card. A question, or a demonstration for your team? Write to us.
latelierdudev.contact@gmail.com
Opens your e-mail app. We only use your address to reply.
