I set an international visitor up with the $30 5GB plan. They would like to retain their current phone number for the next time they're in the US (in ~1 year.) What's the cheapest way to retain the phone number and be able to use the $30 plan again?
Get a Google voice number. T-mobile cam suspend your account for up to 6months but you pay around $10/month for the "favor". IMHO is not worth it the cost.