I installed a Yealink W52P on a NEC SV9100, works great, the customer decided they wanted a 2nd cordless handset and purchased one. The new handset registered as H2, the original handset is H1. The new handset receives internal and external calls but cannot not dial out.

Something I noticed: When I press the speaker key on the original handset H1 line 1 comes up, when I press the speaker key on the new handset line 6 comes up.

The base was setup as extension 191, when I call 191 both handsets ring, when a inbound call comes in both phones ring.

My question is what have I missed that won't allow outbound calls on the 2nd handset?

Been a while since I did one of these but from memory you can have 4 or 5 separate extensions on each basestation called accounts. By default account 1 is used but there should be a dropdown so that you can set up account 2, 3 etc. Below is a Onedrive link to a zip file I put together when I worked for NEC that may help.

https://1drv.ms/u/s!AnwGLt6eGSBBgY4wRg7mGFlPijGAmA

Goodluck

Couple things dans. Make sure IP Duplication is allowed. Also I THINK you have to give it a CAP key.

Paul's advice was correct, handset 1 was using account 1 and handset 2 was using account 2, I duplicated account 2 to match account 1 and handset 2 is now able to dial out.

Thanks Pau!