Number portability
lookup comparisons

Number Portability information supports advanced traffic routing and delivery solutions for Voice calling, SMS messaging, Rich Communication Services, Voice over LTE, Business Messaging, Application-to-Person (A2P) messaging and the communications services of the future.  All applications can use Number Portability information to simplify routing, reducing failures, increase margins, improving service quality and avoiding contract breaches. 

Why do you need it?

Business Messaging – A2P SMS

In most markets, termination fees incur a surcharge if the received traffic is off-net (subscriber doesn’t belong to the terminating network and requires forwarding to the correct network).  In other markets, off-net messages can simply be dropped.  To be assured that messages are delivered in a timely manner and margins are optimised, A2P SMS aggregators check number portability records in real-time prior to attempting on-net message delivery (direct to the network the subscriber belongs to).  

Used in conjunction with number range services (for number validation and basic routing), integrating real-time number portability into routing operations greatly improves operational performance, removing the need for multiple retries, increasing success rates and higher customer satisfaction. 

In the past, the go to tool for number portability was HLR Lookup, but such services don’t scale well and provide inconsistent results.  Consequently most A2P SMS aggregators have migrated to using dedicated number portability services.  Customer access to XConnect NPQ’s unified data via simple, secure, scalable, and real-time query using enum or https interface.  Enum provides ultra low latency and capacity to suit SMS wholesales services of aggregator and hubs whereas https provides the developer convenience required to build modern enterprise A2P web applications. 

Global routing
International voice routing

Prefix routing was commonplace across voice providers.  

Today, IP based interconnects can be established quickly and economically which is resulting in more highly meshed international networks for voice and more advanced services.  This complex meshing opens the door to improved routing efficiency and less complex billing and revenue assurance due to less hops, more capable fraud management systems as well as opportunities for margin improvement.  To unlocking these benefits IP based interconnects make use of number information services such as number portability and number range services.  

Real-time B number portability status enables direct routing and A-number range intelligence enables regional surcharge management, both resulting in a better understanding of the real termination cost which leads to improved margins and lower risks.  In conjunction, B number range and hotlists can remove millions of unnecessary or fraudulent voice calls per day from routing. 

Customer access to NPQ’s unified data via simple, secure, scalable, and realtime query is supported through a choice of enum or sip interface.  Enum provides ultra low latency and capacity whereas SIP provides the developer convenience required to integrate directly with network equipment. 

Comparing Number Portability Services


XConnect NPQ 

HLR Lookup 



Authoritative Data Sources

This is the best type of data for the majority of number portability applications.  Only through sourcing data in this way can you meet the performance, support and accuracy needs of leading voice and messaging providers.   Adding new countries to the coverage becomes increasing complex as there are few standards and significant effort is required to normalise, support, maintain data accuracy as well as meet the performance requirements for a carrier grade service. 


Yes – Over 50 authoritative country databases. 




Number Ranges 

International number ranges, still play a key role in number portability solutions.  For example number ranges can be used to inform  if a number is ported away from the range holder and who the range holder is, provide fallback information where number portability data may not be available, or basic validation prior to initiating more expensive number portability checks. 





HLR Lookup (MNP Only) 

Useful for some applications but HLR Lookup can be 1000 times slower than authoritative sources and can be unreliable, thus making it unsuitable for high volume applications 

To maintain consistency a service needs a network of HLR Lookup providers to be managed in order to overcome the temporary nature of each individual providers coverage. 

Managing multiple suppliers is not easy.  You need network level aggregation and network behaviour is different depending on the history of the number being queried. 



Yes – limited to own variable coverage. 



Data Protection

Telephone number information is personal data and so are the records of number portability lookups (meta-data).  Companies offering number information services are data controllers taking legal responsibility for their services. 





Service Level Agreements

Including fast response times, data quality support and 24×7 helpdesk are vital in order to support the needs of  large scale communication applications. 

Yes – multilingual 





Frequently Asked Questions

Yes.  XConnect has a HLR Lookup service called NPQ-LIVE.  However, HLR Lookup is only suited for low volume applications.  Latency for HLR Lookup can be very high (typically 300-500ms) and high usage can also result in blocking by mobile networks. 

XConnect Number Portability Query (NPQ) only uses HLR Lookup for countries where an authoritative database is not available. 

Access to the number lookup service is via query-response api with the queries telephone number provided as an attribute.  Enum, http and SIP apis are available.  

The majority of the XConnect data (over 50 countries) is sources from authoritative central databases.  Typically this data is 24hours old.  In some countries intra-day updates are available.  Where authoritative sources are not available, XConnect falls back to HLR Lookup.  HLR Lookups provide the most up to date information (minutes old) but is not reliable or fast enough to support high volume applications. 

Service costs are driven by volume and the datasource.  Low volume users where the data source is HLR Lookup, prices start at $0.0025 per lookup, Low volume users where the data source is an authoritative database start at $0.002.  Significant discounts are available for higher volume applications and the largest of users pay a fixed monthly fee for unlimited usage.  Please contact sales for more information. 

Most customers traffic fall into 3 categories.  Firstly, countries where they have huge volumes and direct routing is essential in order to maintain volumes and margins.  Secondly, a mixture of countries where volumes are modest but direct routing can introduce some overall system efficiency as well as potential for small gains in margin.  Finally, a mixture of low volume countries where direct routing would introduce unnecessary complexity and there isn’t enough volume to negotiate better direct route pricing. 

Number Lookup is not always an exact science.  It is as important to know when accurate number portability information is available as it is to know when there are issues with data and how these issues can be resolved.  Most service will only give you information when they have it available and they wont be accountable for the result they provide.  XConnect’s service informs customers when data is unavailable and provides number range information as a fallback and our operations team proactively monitor data quality on a daily basis. 

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