900 is a premium-rate code. The caller pays extra for the call. In service since January 1971.
Premium rate
Area code 900 · Works across the North American Numbering Plan
Send any number and the line type comes back with validity and clean formats. A toll-free or service number is called out by type.
curl -s "https://api.parseapi.com/phone/9005550100" \ -H "X-Api-Key: $PARSEAPI_KEY"