If I have more than one roaming plan which is used first?

Roaming is used on a first bought first used basis

Roaming services
Can I roam and use data if I don’t have a plan?
What are the roaming plans available?
How many roaming plans can I buy?
My roaming is not working what do I do?
Can I roam and make phone calls?
When can I buy the roaming plan?
Can I manually select my operator when I roam?
Where do I see what countries you offer roaming packs?
How do I take a roaming pack?