Invalid numbers 

A number was provided that cannot be a real phone number due to wrong format or is ambiguous e.g. because no country prefix was provided and the number itself could belong to several countries.

You can use our HLR product to verify whether phone numbers valid or invalid.

Examples:

• +5456545451515544 - too long
• 5464654 - country prefix not provided - will only work if the default prefix from user settings fits the intended target country.
• +31fgf6464w54 - contains letters

Inactive numbers

An inactive number is a valid phone number, which is permanently or temporary not active and cannot receive SMS or calls.

Examples:

• Phone is switched off 
• Phone has no reception
• Phone was cancelled/deactivated by the MNO

You can use our HLR product to verify whether phone numbers are active or inactive.

If you have any questions, please send an email to support@sms.to