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Home > Guides > Faxing both sides of ID
Usually yes. The front of your ID shows your photo and name, but the back carries the barcode or machine-readable zone plus details like issue date and restrictions, and most HR departments and tax offices ask for both. The one exception is a passport: the bio-data page is a single page, so there is nothing on the back to fax.
| Document | Which sides? | Why |
|---|---|---|
| US driver's licence | Both | Back carries the PDF417 barcode with encoded identity data plus endorsements and restrictions |
| Canadian provincial licence | Both | Back carries the barcode and conditions (glasses, air brake endorsements, etc.) |
| State or provincial ID card | Both | Same layout as a driver's licence, same back-side data |
| Passport | Bio-data page only | Single page; the machine-readable zone is printed on the same page as the photo |
| Permanent resident card | Both | Back carries the machine-readable lines used for verification |
More than people expect. A modern driver's licence back carries a PDF417 barcode: a dense two-dimensional barcode that encodes your full name, address, date of birth, licence number, issue and expiry dates, and any restrictions or endorsements. Even if the recipient never scans the barcode, the printed details on the back (issue date, class, conditions) are part of what HR and compliance teams verify. Some offices also use the back to confirm the card's security features, which is why a front-only copy can be rejected even when the front is perfectly legible.
HR departments collecting I-9 or onboarding documents, tax offices verifying identity for returns and refunds, banks opening accounts, and landlords running background checks. In practice, "copy of your ID" almost always means both sides in a business context, and faxing only the front is the most common reason an ID fax gets bounced back with a request to resend. When in doubt, send both: an extra page costs little and saves a round trip. The reverse is also true: if someone asks for "the front of your ID" specifically, they genuinely mean just the front.
Faxing both sides doubles the sensitive data in transit, so take the same precautions you would with any ID copy. Fax only to a number you verified with the recipient directly, not one copied from a third-party website. Include a cover sheet stating who the ID is for, so a stray page is identifiable. After the recipient confirms they have it, ask how long they retain ID copies. In Canada, privacy rules require organizations to protect identity documents they collect, and in the US, a fax left sitting in an office output tray is the classic failure mode, so a quick "please confirm receipt" call is worth it.
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