Starting to plan the move, and we would like to keep our UK numbers so were wondering if anyone has any advice on the best UK provider in terms of Roaming in KSA (we will be based in Riyadh if it maters).

When you say ‘best’ do you mean by service or by cost to roam or simply cost to park the number and receive SMS etc ?

Incoming sms is usually free (O2/Tesco experience). Obviously there are charges to receive calls or use data but for banking purposes, you only need incoming SMS and should be good to go.

I have a SIM only package with three. Roaming charges aren't too bad for data, £5-7 a day generally for most places. But don't activate that feature often.

Otherwise, no issues keeping your number active as long as you pay your monthly bill..may even be worth changing to one of those monthly ones like Giffgaff if cost is a worry.