Councils and public buyers: what to mask before publishing decisions and tender documents

Before a council or public buyer puts a decision, minutes or tender file online, it should mask two things. The first is people’s private data. The second is the bidders’ trade secrets. What the public may see must stay visible: the decision, the winner and the total price. This guide compares England, France and Germany as of October 2026. It is information, not legal advice.

Which documents must councils and public buyers publish online?

Which personal data hides in these documents?

A joint 2019 guide by the French data protection authority (CNIL) and the French access-to-documents commission (CADA) lists what counts as private life. It includes postal address, email, phone number, property, income including aid, bank details and disability status. Such data turns up in grants, social aid, land sales, complaints, staff assessments, signed letters and bidders’ CVs.

In England, the Local Government Transparency Code dates from 2015 and cites the old Data Protection Act 1998. It says that law does not restrict publishing information about councillors and senior officers. It adds that the law does not automatically bar naming suppliers, sole traders included. Procurement guidance says a buyer can use a group mailbox instead of one named officer.

In France, personal data goes online in three cases only. Either the person agreed, or a law allows it, or an exception applies. The exceptions sit in article D. 312-1-3 of the French code on relations between the public and the administration (CRPA). Elected members speaking in that role need not be masked in minutes.

In Germany, Lower Saxony’s commissioner (FAQ, January 2024) says a public citizen information system must hold no personal data, unlike a closed council system. Residents’ comments on development plans, with a name and address, need a legal basis or consent, which cannot be assumed. In a 4 February 2019 post, Baden-Württemberg’s commissioner said a city could not lawfully publish such comments with names, addresses and some email addresses.

What can bidders keep secret, and what must stay public?

In England, the Procurement Act 2023 lets a buyer withhold trade secrets, or information likely to harm commercial interests. This needs a public interest test: withholding must outweigh disclosure (section 94). Guidance gives pricing build-up and margins as examples, but says re-bid concerns should not justify hiding the contract value itself. The notice must say that information is withheld, and why. The Transparency Code adds that confidentiality alone is no reason to skip publishing contract details.

In France, the CADA’s sheet on public contracts (updated July 2018) sorts documents into three groups. Notices, the winner’s total price and the list of admitted candidates can be shown. The winner’s application, the commitment form (acte d’engagement) and invoices can be shown once protected items are masked, such as bank details, turnover and private-sector references. The unit price schedule, the price breakdown, the technical memo, and losing bidders’ applications and detailed offers cannot.

In Germany, section 5 of the procurement ordinance (VgV) bars a buyer in principle from passing on information that companies marked as confidential. This covers trade secrets. So ask bidders to mark what is secret. Bids and evaluation records stay confidential after the procedure ends. Section 39 still requires an award notice within 30 days. Details that would harm legitimate business interests or fair competition may be left out. Both rules apply above the EU thresholds.

Why are annexes the biggest trap?

Jane Example, a clerk, prepares a two-line decision granting a housing grant. It looks clean. The annex is a 30-page scan of applicants’ letters with names, addresses, signatures and bank details. In France, the CADA says an act goes online “in its entirety”, annexes included, and that this does not cancel the duty to mask. A text search will not warn you: a scan has no text to find.

What should you check before publishing?

1. Keep the signed original untouched in the official file. Lower Saxony’s commissioner separates the council’s files from documents shown to the public.
2. Work on a copy. Mask page by page, annexes included, but leave visible what the law keeps public: the decision, the winner, the total price.
3. Check the copy. Try to select text under each mask, read every scanned page, and check signatures and handwriting by eye.
4. Note what you masked and why, then publish only the masked copy.

Mind the format too. French rules for local acts require a format that cannot be modified. For open data, the CADA says the format should in principle be machine-readable, not an image PDF. A copy rebuilt from page images may meet the first rule but not the second, so ask which rule applies.

ONYRI Sanitize masks documents in your browser, without uploading them. It finds names, IBANs, ID numbers and amounts with a currency, such as unit prices. Detection of addresses and company identifiers depends on the country: in England it finds postcodes but not streets. It reads scans with OCR. It cannot tell what must stay public, such as the winner or total price: uncheck them in “Detected data”. Bare numbers, signatures and handwriting need “Select text” or “Draw an area”. The export has no searchable text.

Rules change and cases differ. For a doubtful document, ask your data protection officer or legal service before publishing. Do not guess when a name or a price is at stake.

Frequently asked questions

Sources & references