There is a particular kind of small dread that comes with the line "please attach a copy of your ID (front and back)." You have done it before. You photographed the front, photographed the back, and ended up with two crooked images, one of them washed out by a stripe of light where your ceiling lamp bounced off the laminate. The office emailed back asking you to resend. You are now, somehow, a person with a part-time job in document compliance.
It looks trivial, and it isn't quite. An ID card is one of the hardest small objects to scan well, and the request to put both sides on one page is not bureaucratic fussiness — it encodes something real about how the document is meant to be read. Once you understand why, the whole task gets easier and you stop guessing.
Why they want both sides — and on the same page
A government ID is not a single-sided document that happens to have printing on the back. It is one document split across two faces, and the two faces do different jobs.
The front carries the human-readable identity: your photo, name, date of birth, the document number. The back, on most cards, carries the machinery of verification — the signature panel, the issue and expiry dates, the issuing authority's codes, and very often a machine-readable zone (the dense block of <<< characters) or a barcode that encodes the same data in a format a scanner can check against the front. A driver's license back often holds the class of vehicle, endorsements, and restrictions. A national ID back frequently holds the address and the security features that are hardest to forge.
So when a bank, a landlord, or a mobile carrier asks for both sides, they are not collecting paperwork for its own sake. They are asking to cross-check: does the expiry on the back agree with a valid document? Does the machine-readable zone decode to the same name printed on the front? A front-only copy is, to a verifier, half a sentence.
The one page part matters too. When both faces sit on a single sheet, the reviewer can see at a glance that they belong to the same card, photographed in the same session, at the same scale. Two separate files invite the quiet suspicion that the front of one card has been paired with the back of another. A single page is its own small proof of integrity. This is why so many institutions explicitly request it, and why the cleanest version of this task is one image, two faces, top and bottom.
The real enemy is specular reflection
The reason ID cards photograph so badly has a name: specular reflection. Most paper is matte — it scatters light in every direction, so it looks roughly the same brightness from any angle. That scattering is called diffuse reflection, and it is what makes ordinary documents easy to scan.
A laminated ID is not matte. Its surface is glossy, and a glossy surface behaves like a mirror: light arriving at one angle leaves at the mirror-opposite angle, concentrated rather than scattered. When that concentrated beam happens to bounce straight into your phone's lens, you get the blown-out white stripe that erases whatever text was underneath. Worse, modern IDs are designed to do this — the holograms, kinetic images, and optically variable ink that prove the card is genuine are engineered to flash and shift as the angle changes. The very features that make a card secure are the ones that wreck a careless photo.
You cannot eliminate specular reflection by adding more light. Pointing a brighter lamp, or a phone flash, directly at a glossy card just gives you a brighter mirror. The fix is geometry, not brightness.
How to actually do it
Start by getting the light off the mirror-line. Use soft, indirect light — daylight from a window to the side, or a lamp bounced off a wall or ceiling — rather than a single bright source aimed at the card. A broad, soft source has no sharp angle to reflect, so there is no concentrated stripe to land in your lens. Never use the flash on a laminated card.
Then change your angle relative to the light, not the card's position on the table. Hold the phone directly above the card, lens parallel to the surface, and shift your whole body a few degrees until the glare slides off the edge. Watch the live preview — the reflection moves as you move, and there is almost always a position where it falls away entirely. Tilting the card slightly can also work, because you only need to break the mirror angle by a little.
Keep the background plain and dark. A wood table or a sheet of dark paper gives the card a crisp edge, which helps any scanning app find the four corners and crop cleanly. A glossy white countertop fights you twice — once for glare, once for the lost edge.
Now capture the front, then flip the card and capture the back in the same session, at the same distance. Most dedicated scanning apps will let you take two captures and place them on a single page, one above the other — which is exactly the format the office is asking for. If you are stitching it yourself, keep both faces at the same scale and orientation so the page reads as one coherent document. Resist the urge to crop so tightly that you clip the card's rounded corners; a thin margin of background reassures a reviewer that nothing was cut off or hidden.
One more quiet detail: hold steady and let the shot settle. ID text — the document number, the small print on the back — is tiny, and the fastest way to make it unreadable is a half-millimeter of hand shake during capture. Brace your elbows, exhale, and let the image sharpen before you tap.
The part nobody mentions: where the copy goes
Here is the uncomfortable truth about scanning an ID. You are creating a near-perfect digital copy of the single most sensitive document you own — the one that opens bank accounts and rents apartments — and most people then send it through whatever channel is most convenient. Free online "scan to PDF" tools and many scanner apps upload your image to a server to process it. Your driver's license, front and back, now lives on a machine you will never see, under a privacy policy you did not read.
This is the rare case where the how and the where are the same decision. A clean scan you cannot trust is worse than a messy one you can, because the failure mode isn't a rejected email — it's a copy of your identity sitting in someone else's cloud, indefinitely. The safest scan of an ID is one that never leaves your phone: captured, cropped, cleaned, and exported entirely on the device, so the only copy of your identity that exists is the one you deliberately choose to send.
When it finally works
The good version of this task takes about ninety seconds. Soft light from the side. Phone held flat above the card. A small shift of your body until the glare slides away. Front, then back, on one page, corners intact, text crisp enough to read the expiry date without squinting. You attach it once, and the office never writes back.
That is the small competence worth having — not because scanning an ID is hard, but because doing it cleanly and privately, the first time, saves you from both the resend and the regret.
This is the kind of moment LumenScan was built for: it captures both sides of a card onto a single page, finds the edges and tames glare automatically, and runs its OCR and cleanup entirely on your device — your ID is never uploaded to anyone's server. If you'd rather your most sensitive documents stay in your own hands, you can see how it works at lumenscan.lumenlabs.works.