Tax notice: what to hide before you send it, and when the recipient can check it online

Keep the income figures and the tax year, because that is what the recipient wants to see. Hide the identifiers they do not need, unless they check the notice online, as a French landlord can.

This guide covers France, Germany and the UK, as of November 2026. It is general information, not legal advice. For a landlord or a lender, never hide your name, the tax year or the income lines.

Which identifiers can the recipient use to check a tax notice?

Can a French landlord check your avis d’imposition online?

Yes. The French tax office runs a verification service for bodies that ask for proof of income. Its page names a town hall or a landlord as examples. The person checking types two numbers from the notice: the tax number (13 digits) and the notice reference (13 characters, which can include a letter). The service answers “conforme” or “non-conforme”.

“Conforme” means your copy matches the latest notice the tax office knows. According to the same page, “non-conforme” appears when a newer notice exists or when a number was mistyped.

A decree of 5 November 2015 (number 2015-1437) lists what a landlord may ask for in a rental file. According to Service-Public.fr, the official information site, that includes the latest or second-latest tax notice. A copy is enough, but the landlord may ask to see the original. In the online check, a second-latest notice shows “non-conforme”, since a newer one exists.

Your notice also carries a 2D-DOC, a square barcode. The tax office says it lets a reader check that the notice is intact. ANTS, the French agency for secure documents, publishes the 2D-DOC specification. In its December 2021 version, the code must hold your name, tax number and reference taxable income (revenu fiscal de référence). It may also hold the number of parts and the notice reference. The data is signed, not encrypted, so masking the printed numbers does not hide the code.

What do German landlords, nurseries and student-aid offices ask for?

Germany’s data protection authorities (the DSK) updated their guidance for landlords in January 2026. At a viewing, a landlord usually does not need your finances. Only the chosen candidate, just before signing, can be asked for proof. That can be a payslip, a bank statement or a copy of the tax assessment (Einkommensteuerbescheid), with unneeded details blacked out.

The sample notice from North Rhine-Westphalia’s tax administration (tax year 2014, invented people) splits church tax by denomination and lists each child’s birth date. The tax number and tax ID repeat in the header of all nine pages. Article 9 of the GDPR treats religious beliefs as special category data, and the DSK says a blanket question about religion is not allowed. In our reading, church tax lines are fair to hide from a landlord.

Munich’s information sheet for parent-run nurseries (March 2026) asks for the complete notice from the year before last, and a copy is enough. For student aid (BAföG), the City of Munich asks parents for the income and church tax notice from the year before last. It subtracts the assessed church tax from their income. Ask the office before you hide anything.

What does a UK lender need from an SA302?

GOV.UK says you might be asked for an SA302 tax calculation and a tax year overview as evidence of income. Its example is a mortgage application by a self-employed person. You print these documents yourself from your HMRC (UK tax office) account or your software. GOV.UK tells you to check that your mortgage provider accepts documents you printed yourself.

GOV.UK does not list the identifiers printed on the calculation. Check your copy for your Unique Taxpayer Reference (UTR) and your National Insurance number. The GOV.UK list of lenders that accept these documents dates from June 2020, so ask your lender.

Can you give a tax notice to an AI assistant?

Yes, if you remove what identifies you and keep what the question needs. Mask your name, address, tax numbers and IDs, notice reference, UTR and National Insurance number. Mask your partner’s and children’s names and birth dates. On a French notice, cover the 2D-DOC barcode too, because it repeats your tax number.

Keep the figures: income, tax due, allowances and the tax year. Without them, an assistant cannot explain a bill or check a calculation. If a question needs one detail, such as a church tax line or a child’s age, keep only that line. A rare mix of amounts and dates can still point to you. The assistant reads everything you leave visible, so send the masked copy and keep the original on your device.

How do you mask a tax notice and check the result?

1. Ask the recipient what they need to see. Will they check the notice online? Do they want every page?
2. Mask on every page the identifiers you decided to hide. The official German sample repeats the tax number and tax ID in each page header.
3. Leave the income figures and the tax year visible. Check each amount and date that the tool masked by default.
4. Draw over the 2D-DOC barcode if you hide the numbers, unless the recipient will scan it. Detection looks for text, not barcodes.
5. Read the final copy page by page and compare it with the original. Look at headers, footers and stamps first, where a number can stay visible.

ONYRI Sanitize masks names, address, French tax number, amounts with a currency and full dates by default, in your browser. Untick in “Detected data” what the recipient needs, such as the tax number for an online check. Not reliably detected: church tax lines, the notice reference, the online access number and the UK UTR. Add them with “Also mask” or “Select text”. Over 5 pages: the 7-day pass or Pro.

Send the masked copy only to the person who asked for it, and say what it is for.

Frequently asked questions

Sources & references