Premium-rate phone numbers (such as +1900 numbers in the US and +449 numbers in the UK) are phone numbers typically used to provide information, customer support, or entertainment on a shared-cost basis. This means that the callers are charged a higher per-minute rate on their phone bill which can be upwards of $1 or more per minute. The extra toll collected is given back to the owner of the phone number to partially fund the cost of the inbound call. As such, these phone numbers are more likely to be used for fraudulent purposes and Twilio doesn't provide premium-rate phone numbers in any country at this time.