Originally Posted by FlyingSmurf

There is a bus between T2 and T5 airside.

I have found this online:

Transfer between Terminal 2 and Terminal 5 - after security

Travels within SchengenFor you who is travelling within the Schengen area and is transfering between Terminal 2 and Terminal 5, there is a transfer bus. The bus stops at the following places:

• Gate 61C in Terminal 2
• Transfer Gate T11 by the passage that binds Gate area C with the rest of Terminal 5
• Gate F5 in Terminal 5

The bus is manned every day between 05.30-22.00. Request pick-up by pressing the button at the transfer bus stop. The bus will arrive within 20 minutes.
https://www.swedavia.com/arlanda/tra...t-the-airport/