What's the difference between single-side and dual-side document scanning?

Single-side scanning captures only one face of a document, while dual-side scanning captures both front and back, and which one a given document actually needs depends entirely on where its data physically lives.

Passports are the clearest example of a document that only requires single-side scanning: the biographical data page contains the photo, the visual zone with the holder's personal details, and the MRZ, all together on one page. There's simply no additional identity data on the passport's other pages that a standard scanning flow needs to capture (aside from visa stamps or entry records, which aren't part of standard identity extraction).

National ID cards and driver's licenses are usually different. Many carry the photo and core visual zone fields on the front, while the back holds an MRZ (for ID cards that include one), a barcode (very common on North American driver's licenses, encoding data in AAMVA format), or additional fields like an address that wouldn't fit alongside the photo on the front.

For these document types, single-side scanning of the front alone would miss a meaningful share of the available data, particularly the barcode-encoded fields that are often the primary structured data source for driver's licenses specifically.

From a user experience standpoint, single-side scanning is naturally faster, since it's a one-step capture rather than a guided two-step flow (scan front, flip document, scan back). This is part of why document scanning products designed for speed, like fast hotel check-in or quick age-verification at a retail counter, often emphasize single-side scanning specifically for document types like passports where it's sufficient, while still offering dual-side capture for documents that genuinely require it.

A well-built scanning solution should automatically determine, based on the recognized document type, whether single-side or dual-side capture is needed, rather than requiring a business to configure this manually for every document type it might encounter.

ScanDoc's engine automatically detects whether a given document type needs single- or dual-side capture, defaulting to the faster single-side flow for passports and similar documents while guiding users through a dual-side capture for ID cards and driver's licenses that carry meaningful data on the back.