Veriphone provides a phone number validation service. But the term Validation or Valid can be confusing. What does a valid phone number mean and what is the difference between Valid, Active and Online?
TL;DR;
A phone number goes through multiple stages in a complex lifecycle that we will describe in this short article. An over-simplification that, we hope, will help you understand the difference between the three main stages: Valid, Active and Online.
A phone number starts as just a number inside a large range of numbers considered for use by a country's telecom authorities. Once approved for use, the number (or rather a range of numbers) will be assigned to a line-type and a carrier. We will call this carrier the original carrier (more about this in the next section). For fixed-line numbers a country region will also be assigned.
Once approved and assigned to a carrier and line-type, a number is said to be valid. From this point on, the carrier takes over the management of the number from user assignement to network registration, porting or roaming.
Carriers will put their assigned numbers on the market for acquisition by users. Once acquired by a user and connected for the first time to the wireless network, the number is said to be Active.
If the number is disconnected from the network (phone switched off or in airplane mode) the number is still considered active. It will go back to unactive mode only if the carrier terminates the user's contract and put the number back on the market for acquisition
A user might decide to change the Carrier but keep the same number. Once the transfer to a new carrier is done, the number is said to be Ported
A user might also move temporarily to an area where the original or ported carrier do not have coverage. If the number is registered by a partnering carrier, the number is said to be Roaming.
All three states above provide no guarantee about being online or reachable. A phone can go off and SIM card be destroyed and still show as Active, Ported or Roaming depending on the last known state.
Finally, when a number is registered on a network using a working phone, ready to receive calls, the number is said to be Online
If the number is not detectable on any network, it is said to be Offline
Veriphone is a first stage validation service. We tell if the number is Valid, provide the line type and original carrier. If you need to find if a number is Active, Ported, Roaming or Online, see this table comparing other providers.