Some older or USB-only models do not have a web interface. The password is only for TM-T20III models (those with an Ethernet port or optional Wi-Fi module).
Use epson as the username and your serial number as the password. Troubleshooting Login Issues If the serial number does not work: Epson Firmware password - POSdata.eu epson tm-t20iii default admin password
If this fails, try admin / epson or blank username with 0000 . If still no luck, the printer may have been previously configured by a POS vendor. Some older or USB-only models do not have a web interface
The Epson TM-T20III is a popular thermal receipt printer used in retail, hospitality, and healthcare environments. While it is primarily a "plug-and-print" device, accessing its built-in web interface (EpsonNet WebManager) or configuration manager requires an administrator password. epson tm-t20iii default admin password