Sinch Fax API
Ranked in SIP Trunking Providers ·No free plan on record
About
Sinch Fax API is a cloud-based service for sending and receiving faxes through a REST API. It supports inbound and outbound faxing, delivery tracking, and webhooks for arriving or completed faxes. Authentication is available through Basic or OAuth 2, while enabled storage retains fax logs and media for 13 months before deletion. Supported content includes DOC, DOCX, PDF, TIF, JPG, TXT, PNG, URLs and HTML. Its portal shows fax activity times and status and lets teams manage users, groups, roles and permissions. Customers can select local or toll-free numbers or bring their own. Sinch describes intelligent routing and automatic retries, and states that its U.S. fax-processing network has 99.999% uptime and redundant infrastructure. A free Sinch Build Dashboard account is required to begin, and signup includes a virtual number for testing. Pay-as-you-go is listed at 0.05 USD per page. A Fax API service can have only one webhook at a time, limiting it to one inbound fax trigger in Zapier.
Who it is for
It suits startups and established companies that need API-based faxing, with stated use cases in healthcare, legal, finance, insurance and real estate. Teams using Zapier inbound fax triggers should account for the single-webhook limit.
What is good
- Supports inbound and outbound faxing with delivery tracking.
- Basic and OAuth 2 authentication are supported.
- Automatic retries and intelligent routing are offered.
- Portal manages users, groups, roles and permissions.
- SDK languages include Node.js, Java, .NET and Python.
What to know first
- Only one webhook can be configured per service.
- Enabled storage retains fax logs and media for 13 months.
- Pricing is otherwise available on request.
Verdict
The API combines fax delivery, status events and number options with a customer management portal. Confirm webhook capacity, storage behavior and page pricing against your workflow.
Compared on SIP trunking providers
Facts
- What it does
- Sinch Fax API is a cloud-based service for securely sending and receiving faxes through an API.sinch.com · 4 Oct 2026
- Routing and retries
- The service offers intelligent routing and automatic retries for failed fax transmissions.sinch.com · 4 Oct 2026
- Reliability
- Sinch states that its network has 99.999% uptime and redundant infrastructure for fax processing in the U.S.sinch.com · 4 Oct 2026
- Security
- Sinch says the service supports HIPAA, SOC 2, and GDPR compliance needs, and describes advanced encryption and secure transmission methods for healthcare data.sinch.com · 4 Oct 2026
- File formats
- The product page lists DOC, DOCX, PDF, TIF, JPG, TXT, PNG, URL, and HTML content as supported formats.sinch.com · 4 Oct 2026
- Dashboard
- The customer portal can show fax send and receive times and status, and lets users manage users, groups, roles, and permissions.sinch.com · 4 Oct 2026
- Numbers and scale
- Customers can choose from millions of local or toll-free numbers or bring their own, and Sinch says its infrastructure scales for high fax volumes.sinch.com · 4 Oct 2026
- Integration
- Sinch documents a Zapier integration with an inbound fax trigger and a send-a-fax action.developers.sinch.com · 4 Oct 2026
- Integration limit
- A Fax API service can have only one webhook at a time, which allows one inbound fax trigger per service in Zapier.developers.sinch.com · 4 Oct 2026
- API and retention
- The Fax REST API supports Basic or OAuth 2 authentication, webhooks for arriving or completed faxes, and—if storage is enabled—retains fax logs and media for 13 months before deletion.developers.sinch.com · 4 Oct 2026
- Free account
- The getting-started guide says Fax API use requires a free Sinch Build Dashboard account and that signup includes a free virtual number for testing.developers.sinch.com · 4 Oct 2026
- Support
- Sinch offers product contact through its sales team and developer documentation, and the API reference directs users with questions to the support portal.developers.sinch.com · 4 Oct 2026
- Intended users
- Sinch describes the API for startups and established companies, with examples spanning healthcare, legal, finance, insurance, and real estate.sinch.com · 4 Oct 2026
Company
- Founded
- 2008sinch.com · 28 Sept 2026
- Headquarters
- Stockholm, Swedensinch.com · 28 Sept 2026
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Where it ranks on Inferse
Sources
- sinch.com/voice/fax-api/· checked 4 Oct 2026
- developers.sinch.com/docs/fax/integrations/zapier· checked 4 Oct 2026
- developers.sinch.com/docs/fax/api-reference/fax· checked 4 Oct 2026
- developers.sinch.com/docs/fax/getting-started· checked 4 Oct 2026