For users of Star printers that communicate with iOS devices of iOS 13.0/iPadOS 13.1 or later using Lightning-USB

We have confirmed that Star printers sometimes cannot print correctly when communicating via Lighting-USB with iOS devices of iOS13.0/iPadOS 13.1 or later (referred to as “target OS”).

This issue has occurred due to the specification change of the target OS. We have released the printer firmware to solve this issue. If you are using the following printers, please update printer firmware.


  • TSP143IIIU (except LAN, wireless LAN and Bluetooth models) : printer firmware V1.0~1.6
  • MCP31L/ MCP31LB (except MCP30) : printer firmware V1.0~2.1
  • MCP21LB (except MCP20) : printer firmware V1.0~2.1


When printing via Lightning-USB with the above models, we have found some phenomenon such as printing mistakes occur once every tens of times.

The following errors have been reported to date. In the theoretical worst case, data loss may occur.

The connected drawer tries to open repeatedly.
The printer ejects long blank paper and some unnecessary characters are printed in some places.

According to our survey results, when data of an integer multiple of 64 bytes is sent from the target OS device, Zero-Length Packet (ZLP) is added to the end of the data. The printer does not perform the correct process triggered by ZLP reception and cannot print normally.

The specification that adds ZLP at the end is not confirmed before iOS12, so we have judged that the cause is the communication specification change after iOS 13.0/iPadOS 13.1.

【How to solve】

Please see the procedure below to update the firmware of your printer.

※The data size of new printer firmware is not integer multiple of 64 bytes, so this issue does not occur when updating the printer firmware via Lightning-USB.