ACR40U vs ACR40T: Which Form Factor Do You Need?
“ACR40U vs ACR40T: Which Form Factor Do You Need?”
Meta description: The ACR40U and ACR40T are both current ACS contact smart card readers — but built for different jobs. Here’s how to pick the right one.
The ACR40U and ACR40T get confused constantly because they share a name prefix and a launch generation — but they’re built for genuinely different jobs. Neither replaces the other; they solve different problems.
The core difference: card size and use case
ACR40U is a full-size desktop reader — it takes a standard credit-card-sized smart card, sits on a desk (or is held via its Premium stand), and connects to a PC like any peripheral. This is the direct replacement for the obsolete ACR39U.
ACR40T is a SIM-sized reader — genuinely tiny (as small as 44.7 × 17.7 × 8.0 mm), with a sliding card-entry slot for a SIM-format card, not a full-size one. It’s built for embedding into terminals, kiosks, or custom hardware where a desktop reader wouldn’t fit or make sense.
If you’re outfitting an office desk or a general-purpose PC station: ACR40U. If you’re building a kiosk, a custom terminal, or embedding a reader into a product: ACR40T.
Spec comparison
| Feature | ACR40U (Standard) | ACR40T (Standard) |
| Card format | Full-size ISO 7816 | SIM-sized (2FF) |
| Dimensions | 55 × 65 × 9.0 mm | 44.7–48.9 × 17.7 × 8.0 mm |
| Weight | 40 g | 5.3–6.8 g |
| Interface | USB Type-A / Type-C | USB Type-A / Type-C |
| LEDs | 2 (status) | 1 (green) |
| Firmware upgrade | Yes | Yes |
| On-device data storage | Yes | Not listed |
| Premium variant adds | Desk stand | Built-in button |
| OS support | Windows, Linux, macOS, iOS, iPadOS, Android | Windows, Linux, macOS, iOS, iPadOS, Android |
Standard vs Premium — same logic on both
On both product lines, Premium isn’t a different reader — it’s the same electronics with one physical addition:
- ACR40U Premium adds a stand for upright or horizontal desk positioning.
- ACR40T Premium adds a physical button, used to confirm user presence for certain application flows (like requiring an explicit tap-to-confirm on a payment or access event).
Unless you specifically need that addition, Standard is the simpler, cheaper choice on both lines.
Quick answers
Can the ACR40T read the same cards as the ACR40U? Only if the card is SIM-sized — the ACR40T’s slot physically won’t accept a standard credit-card-sized smart card.
Is one of these a replacement for the ACR39U? The ACR40U is — same full-size format, same general use case. The ACR40T serves a different, embedded use case the ACR39U wasn’t built for either.
Which is cheaper? The ACR40T’s smaller size doesn’t necessarily mean lower cost — contact BSD InfoTech for current pricing on both.
Full specs for both: ACR40U product page · ACR40T product page. Need help choosing for your specific application? Get in touch.
Need help with ACR40T? BSD Infotech supplies the hardware, builds the software and integrates both.
Request a Quote