How to redact a passport or ID card (and what to hide)

Redacting a document sounds technical, but it comes down to one idea: cover the fields a stranger could use to be you, and keep only the fields that prove you are you to the person asking. Get that split right and a copy of your passport or ID becomes almost useless to a fraudster while still doing its job.

What to hide

These are the fields that do the damage if they leak. Cover every one of them:

• The document number — passport number, DNI/NIE number, or ID card number.
• The machine-readable zone (MRZ) — the two lines of <<< characters at the bottom of a passport, or the code block on the back of an ID card. It re-encodes the number, your date of birth and expiry, so hiding the number alone is not enough.
• Date and place of birth.
• Your signature.
• The support / CAN number on the back of many national ID cards, and any parents’ names printed there.
• Issue and expiry dates, unless the recipient specifically needs to confirm validity.

What you can usually keep

Leave visible only what the recipient must actually match:

• Your name.
• Your photo — so a hotel or rental desk can match your face to the booking.
• Nationality, where it is relevant to what they are checking.

When in doubt, hide it. It is far easier to send a second, less-redacted copy than to claw back one that showed too much.

A note on blur versus solid bars

Not all redaction is equal. A solid bar removes the pixels entirely and cannot be reversed. Heavy blur or light pixelation can, in some cases, be undone by software — so keep those for low-stakes areas and use solid bars over the number and MRZ. Whatever you use, flatten the result into a new image; never send an editable file with removable layers on top.

The steps below walk through the whole process. Anonymize my ID does each one on your phone, offline, in about a minute — but the sequence is the same whichever tool you use.

Redact a passport or ID, step by step

1. Start from a clear photo, offline. Photograph the document on a plain background in good light, or pick an existing photo. Use an app that works entirely on your device so the image is never uploaded.
2. Cover the number and the machine-readable zone. Place solid boxes over the document number and the two code lines at the bottom. These two fields are what most document fraud relies on.
3. Hide your date of birth and signature. Add your date of birth and handwritten signature to the redaction. Leave your name and photo visible only if the recipient must match them.
4. Use partial redaction where it helps. If someone needs to confirm only the last few digits of a number, reveal those and hide the rest.
5. Add a watermark tied to the recipient. Write who the copy is for and the date across the whole image, tiled so it cannot be cropped out — for example, 'For visa application, 30 June 2026'.
6. Export the redacted copy — and only that. Save or share the redacted, watermarked version, never the original, and delete the copy once it has done its job.

Frequently asked questions