The licenses inside the On iN is only for 2 x Aids and not 2 x pairs of Aids.
The actual Microphone tho, can select to 100 sets of Aids I believe or is it 99?
To connect to more Aids, the other set of Aids needs to have the licenses installed or receivers attached to the Aids to work.
EDIT - you could install 1 x license into your private Aids and 1 x license into the NHS Aids.
I have two sets of Bluetooth Aids and only have a Roger license in both right Aids because my right ear is better than my left ear, that doesn’t really pick up much speech anyway.
Not as good as having one in both ears tho for other people tho.
Just thought tho, you could just transfer licenses back into the On and then back out to your NHS Aids if you need to change Aids but if your private Aids end up dead for whatever reason, that won’t be able to happen.