Assuming you are talking about a US Number. Most likely, even if the number you get is not classified as voip today, there's a good chance it will be classified as such in the future. (I've had numbers that I ported to google voice from cell phone that eventually started being classified as a voip #).
Cheapest reliable (as in 100%, GV works ok for me in general, but not perfect) way I've found in my research of this is to get a Tello Mobile #, as they are just a t-mobile MVNO, so the numbers are part of t-mobile's pool, so that costs $5-6 a month at the minimum, depending how you configure it.).
Comments
Assuming you are talking about a US Number. Most likely, even if the number you get is not classified as voip today, there's a good chance it will be classified as such in the future. (I've had numbers that I ported to google voice from cell phone that eventually started being classified as a voip #).
Cheapest reliable (as in 100%, GV works ok for me in general, but not perfect) way I've found in my research of this is to get a Tello Mobile #, as they are just a t-mobile MVNO, so the numbers are part of t-mobile's pool, so that costs $5-6 a month at the minimum, depending how you configure it.).