SINCH’S PHONE NUMBER API 

Automate global number management with a phone number API 

The Sinch Number API is a core component of our API platform, powering SMS, Voice, and Verification solutions. Use one REST interface to search, provision, and configure virtual numbers across 70+ countries and automate SMS, Voice, and Verification with >99.95% availability. 

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Trusted by 190,000+ customers around the world

WHY SINCH 

One unified phone number API for instant, scalable number provisioning 

Make every stage of number management easier from search to release. A developer-first interface helps you be more efficient, accelerate product velocity, and keep global reliability without the hassle of juggling multiple vendors or portals. 

Efficiency at scale  

Say goodbye to manual purchasing with on-demand provisioning and configuration, so teams can focus on product, not busywork.

Faster product cycles

SDKs, sandbox tools, and clean docs let developers integrate SMS, Voice, or Verification features in hours, not weeks.

Resilient operations

Programmatically rotate, replace, or release numbers to handle damage, growth spikes, or regulatory changes with ease.

AUTOMATED EFFICIENCY 

Replace slow, manual workflows with full automation 

Automate number search, purchase, and setup in minutes with the Sinch Numbers API.  Free your engineers from portal clicks and spreadsheets while you scale to millions of numbers across 70+ countries with >99.95% availability. 

  • Instant provisioning via API 

  • Automated SMS & Voice configuration 

  • Search global inventory by country, type, capability 

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DEVELOPER VELOCITY 

Launch communication features faster than ever 

Give developers a unified, well-documented API, plus SDKs and sandbox environments. Make operational bottlenecks a thing of the past, so new products ship on schedule and customers see value sooner. 

  • One consistent REST interface 

  • Robust documentation and SDKs 

  • Submit compliance docs programmatically 

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RESILIENT SCALABILITY

Keep communications live through growth or disruption 

Uptime stays high with a globally distributed service. Programmatically rotate or replace numbers to manage traffic spikes, number damage, or evolving regulations—without impacting users. 

  • SLA of >99.95% availability 

  • ISO 27001, GDPR, STIR/SHAKEN compliant 

  • Five AWS regions for global redundancy 

  • Supported in over 115 languages for global voice applications 

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REAL-WORLD USE CASES 

How teams use the phone number API 

Sinch’s cloud communications suite supports PSTN, SIP, WebRTC, and integrates easily with CCaaS and UCaaS systems. 

SaaS platform enablement  

Provision a unique virtual number for every new customer, powering white-labeled SMS, Voice, or Verification features straight from your app.

Dynamic campaign numbers

Secure, configure, and retire dedicated numbers automatically for time-sensitive marketing campaigns and track performance in real time.

Contact center automation

Assign numbers to agents or IVRs on demand, create a regional presence, and mask user identities for privacy-first support experiences.

Number rotation for high volume

Cycle through a pool of numbers to balance traffic, improve deliverability, and protect sender reputation during large-scale messaging bursts.

WHAT’S INCLUDED 

Everything you need in one API 

API-based number search

Filter a global inventory by country, capability, and type to find the perfect number in seconds.

Instant provisioning

Rent and activate numbers on demand—no ticket queues or manual approvals for most markets.

Automated configuration

Programmatically link numbers to SMS, Voice, or callback URLs so they’re ready to use immediately.

Unified REST interface

Manage 10DLC, Toll-Free, and Short Codes with the same endpoints and authentication flow.

Global inventory access

Tap into millions of virtual numbers across 70+ countries for true international reach.

Number releasing

De-provision numbers instantly to control costs and keep your inventory lean.

Compliance tooling

Submit required end-user documentation via API to streamline 10DLC and country-specific registrations.

Enterprise grade security

HTTPS, API keys, ISO 27001 certification, and GDPR & STIR/SHAKEN compliance protect every request.

Frequently asked questions

A phone number API lets you search, provision, configure, and release virtual numbers programmatically. Use it to power SMS, Voice, and Verification in your applications.

Sinch’s cloud communications suite supports PSTN, SIP, WebRTC, and advanced programmable voice features such as Interactive Voice Response (IVR) and Text-to-Speech (TTS). Seamless integration of Programmable Voice capabilities empowers businesses to deliver rich customer interactions at scale. 

Yes. Contact our team to discuss porting requirements, and once transferred, you can manage those numbers programmatically like any Sinch-rented number. 

The API surfaces each type. Our docs explain ideal scenarios, and support can guide you to the best fit based on your traffic, use case, and compliance needs. 

Submit end-user and use-case documentation via API as part of provisioning. This streamlines approvals for country-specific and 10DLC registrations. 

All associated routing and service links are removed immediately, so make sure you update dependent systems before releasing a number. 

You’ll need a Sinch account, API keys, and a backend capable of REST integrations and webhook handling. Sample code and SDKs are available.

The API itself is free. You pay a monthly rental fee per number, varying by type and country, plus standard SMS and Voice usage charges.

All traffic is encrypted via HTTPS and authenticated with API keys. Sinch is ISO 27001 certified, GDPR compliant, and supports STIR/SHAKEN for US anti-spoofing.