Depending on where the customer is roaming from and to, they might risk a per-SMS charge, suffer unreliability, get no signal, or even turn off their phone to avoid accidentally running up a big roaming bill.
When I went from the UK to Montreal, I tried to use local Uber competitor "Teo Taxi" but was unable to as their number-confirmation SMS didn't arrive.
When I went from the UK to Montreal, I tried to use local Uber competitor "Teo Taxi" but was unable to as their number-confirmation SMS didn't arrive.