# Mobile number portability (MNP)

> Mobile number portability lets a subscriber keep their number when changing operator, so the prefix of a number no longer guarantees which network will receive the message.

Before portability, a number's prefix identified its operator. Now, in most countries, a number can belong to any operator. Routing therefore needs a portability lookup on the carrier side to find the current network; a route that ignores porting delivers to the wrong SMSC and fails or is delayed.

Portability also affects sender rules and prices when operators within a country behave differently. The route, not the sender, has to resolve this per message.

At SMSMeteor: porting is resolved on the route; the report names the operator that actually handled a message when a failure carries a reason.

Related terms: [HLR lookup](https://smsmeteor.com/glossary/hlr-lookup), [SMS route](https://smsmeteor.com/glossary/sms-route), [MSISDN](https://smsmeteor.com/glossary/msisdn)

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Source: https://smsmeteor.com/glossary/number-portability (HTML). Generated by SMSMeteor from the same data as the page. Summary of the whole site: https://smsmeteor.com/llms.txt