Sinch Community

  1.      Does Number Lookup V2 work in the same way as legacy Sinch Number Lookup services?   No. Older Number Lookup services typically use Home Location Register (HLR) Lookup as the data source.  Sinch’s first release of Number Lookup is based on data derived from National Regulators.  This means that the results and how those results have been derived cannot be exploited by use-cases in the same way.   2.    What is the difference between Number lookup API and HLR Lookup?   HLR Lookup is usually a live-lookup into a Mobile Operators subscriber database.  However, some suppliers of this service use a cached lookup to save money.  A valid response to a Telephone Number request from a HLR Lookup usually means a Telephone Number is active on the mobile operators network.  The problem with this approach is that it exposes the mobile operator to personal data-loss, since operators never intended to provide access to such information.  It is quite difficult for operators to removed access to such a service, but they have found ways to limit access as well as obfuscate any information provided.    This has led to significant changes in availability and accuracy of information from HLR Lookup.  For instance, a HLR Lookup, if available, will typically only provide intelligence that a Number does belong to that operator, but cannot be relied upon to be live in the network or located in particular part of the global cellular network.   Sinch Number Lookup provides a more consistent set of results since it is based on regulator data.  When a response is returned, it returns information about how the national regulator has assigned a number to an operator.  This does not mean it is active, but that the number is available for use by an operator.   3.    Will Number Lookup API meet my needs?   HLR Lookup may have previously supported multiple use-cases: Message routing, with Port-correction Special permission is now required by Mobile Network Operators (MNOs) to perform this function.  This use-case is no longer supported.  However, in North America, Sinch Number Lookup is port corrected and can be used for routing.  Sinch may add port-corrected results globally in the future.   List Cleaning for “active numbers” HLR Lookup may have supported this use-case several years ago, but changes in the mobile operator have reduced the efficacy for such a use-case.  This is no longer supported.  However, Sinch Number Lookup will help you understand if a number is properly formatted and of a line-type you might expect for a customer engagement.  It is important to remember that any customer list you have must comply with Data Protection laws and if it does, then the relevance of an ‘active number’ service is diminished.   Subscriber Location HLR Lookup would previously return the network address, country location and roaming country of a mobile subscriber.  Since 2018, this is no longer the case, since location is a sensitive subscriber attribute.  All operators have made significant efforts to block access to this information.   4.   Will all the missing features in the legacy API be replaced?   No. Sinch is building a Number Lookup product and roadmap that aligns robustly with global data protection regulations.  However, Mobile Operators are releasing new capabilities that such new data items (such as location), but doing so with a consent mechanism built in.  Sinch will be introducing these services as and when they become available from mobile operators. ... View more

Q: What is changing with the Number Lookup service? We're upgrading to the new Number Lookup API — built on updated data sources with improved data quality, broader coverage, and new capabilities like additional fraud signals. This replaces the legacy Number Lookup product.   Q: Why is this change happening? The new API delivers: Improved data accuracy and compliance New features such as SIM swap detection, reassigned number checks, and advanced VoIP detection A more scalable, future-proof architecture aligned with emerging industry standards like CAMARA Q: When do I need to migrate? The legacy Number Lookup product reaches end of life at the end of 2026. You should start your migration now to allow sufficient time to plan, integrate, test, and cut over without disruption.   Q: Is this migration mandatory? Yes. The legacy Number Lookup API will be retired at the end of 2026, and all customers must migrate to the new Number Lookup API before then. After retirement, the legacy API will no longer be available. New features and enhancements are only being developed on the new API.   Q: What do I need to do to migrate? Sign an updated agreement — a contract amendment or new order form is required due to changes in data providers. Update your integration — the new API uses a new endpoint ( lookup.api.sinch.com/v2/ ) and updated OAuth authentication. Test in parallel — we recommend running the new API alongside your legacy integration to validate results before switching over. Q: Is the new API backward compatible with the legacy one? No, the new API is not backward compatible. You will need to update your endpoint,  authentication method, and integration code. We provide full documentation and support to make this as smooth as possible.   Q: What's the difference between the legacy API and the new Number Lookup API? A detailed comparison guide is available here.    Q: Is MNP (Mobile Number Portability) supported in the new API? MNP is supported in North America. For the rest of the world, number range intelligence provides equivalent routing-relevant data. If you require global MNP, please contact your Account Manager to discuss options.   Q: Can I test the new API? Yes. To get started, sign up for a Sinch Dashboard account and begin testing the new Number Lookup API. If you need assistance with onboarding, please contact your Account Manager or our Support team.   Q: Where can I find the API documentation? Number Lookup API Specification Sinch Number Lookup one-pager Q: Who do I contact for help? Reach out to your Account Manager to get started. If you're unsure who your Account Manager is, please contact our Support team through the Support portal or email [email protected].  ... View more

1.   The data for non-US/CA are not port corrected. What are the values of these data?   Cost efficiency: Non-port corrected data is significantly cheaper than real-time HLR lookups because it doesn’t require access to live network feeds.  Performance and Scalability: Without the need for real-time lookup, non-port corrected data offers faster lookup times, making it highly scalable for bulk operations.  Workflow optimization: If the a number is ported, the line type will remain the same. Enterprise can categories the numbers based on line type attributes for campaign targeting and fraud mitigations. Routing value: For customer requires live routing, non-ported corrected data is not designed for it, it can still meet basic routing needs.   2.   What is the rate limit for the Number Lookup API?   To enhance our service efficiency, we have implemented a rate-limiting mechanism for the Number Lookup API. The Number Lookup API offers three tiers to cater to different customer needs. If premium or custom tier is required, please contact us to enable it.   Tier Requests per second Basic Tier (default) 10 Premium Tier 100, available upon request via our support team Custom Tier For enterprise customers with specific requirements, the rate limit can be customized based on your application configuration. Please contact our support team to discuss your needs and configure the rate limit accordingly.   3. Is Number Lookup subject to HIPAA compliance?   No, Number Lookup is not subject to HIPAA because it does not process, store, or associate phone numbers with health-related data. While telephone numbers are considered PHI, HIPAA only applies when they are linked to medical information. Since Number Lookup does not process PHI, a Business Associate Agreement (BAA) is not required.  4. Why do you need use case approval for Line type feature enablement?   In the US, the data we use comes from the NPAC (Number Portability Administration Center). NPAC has strict contractual terms and conditions that govern its usage. To remain contractually compliant with our supply agreements, we must ensure customers declare their intended use of this data.   5. Why am I not getting the correct carrier after porting my number? Is the data wrong because the operator is different?   In nearly all countries, numbers are assigned by the regulator to an operator, and this assignment is persistent. We use this persistent relationship to define the line type, and it does not change. When a number is ported to a different operator, it is essentially loaned to the new operator, but the original operator assignment remains the same. If the number is ported again or disconnected, it is typically returned to the original operator before any further action is taken. ... View more