SMS Deliverer
SIMCom SIM800C: SMS compatibility and AT notes
A compact 2G module with a mature AT set. Not tested by us, and the 2G shutdowns make coverage the first thing to check, not the software.
2G GSM moduleGSM/GPRS quad-band 850/900/1800/1900 MHzNot tested by us — vendor specs only
Verdict
A compact 2G module with a mature AT set. Not tested by us, and the 2G shutdowns make coverage the first thing to check, not the software.
Specification and SMS behaviour
| Chipset / module | SIMCom SIM800C 2G module, LCC package, 17.6 × 15.7 × 2.3 mm |
|---|---|
| Interfaces | UART for control and data (the USB pins are debug only) |
| Power supply | 3.4–4.4 V supply (4.0 V recommended); the supply must sustain 2 A transmit bursts |
| AT command notes | Mature 2G AT command set; vendor documentation covers text and PDU mode SMS. UDH-based concatenation on this module is not verified. |
| Concatenated (long) SMS | Not verified |
| Receiving SMS / OTP | Not verified |
| MMS | SIMCom publishes an MMS application note (CMMS command set) for the SIM800 family; not evaluated by us. |
| Date tested | Not tested by us — vendor documentation only (as of 2026-11) |
Fields we could not verify are written as "Not verified" rather than filled with estimates.
Known failures and troubleshooting
- 2G sunset: many carriers have shut down or are shutting down 2G — confirm local coverage before choosing a 2G-only module.
- Supply sag below about 3.4 V during transmit drops network registration mid-send.
- UART-only control: a USB-UART bridge is required to use it from a PC.
Data sources
Related pages
Other models
Questions about this model
Is the SIM800C a good choice for new SMS projects?
Only where 2G coverage is confirmed for the life of the project. Many carriers are shutting down 2G; a 4G module is the safer default.
Can the SIM800C connect to a PC over USB?
Its USB pins are debug only. Use the UART through a USB-UART bridge for PC integration.