T42's SIP firmware to Skype for Business firmware

[Evan_Yealink]

Hi Brenton,

Thanks for contacting us! This is Evan from Yealink Support Team. I'm glad to answer the question for you!

1. Below is the download link of the SFB firmware:
http://download.support.yealink.com/down...9.0.25.rom

Note: After upgrading, please reset the phone to factory first. (Long press the OK button about 6s)

2. For the license, please refer to below FAQ: Free now! Also permanent!
http://support.yealink.com/faq/faqInfo?id=380

3.Yes you can, just need upgrade the firmware form SFB to SIP firmware. Below is the download link of the T42S SIP firmware.
http://download.support.yealink.com/down...3.0.10.rom

Note: Also after upgrading, please reset the phone to factory first.

By the way, please use our ticket system to raise questions, it is better technical support Service and best support experience.
https://ticket.yealink.com

Please don't hesitate contact us if anything we could help. Hope you have a nice day!

Best Regards,
Evan You