Portability Check | Frequently Asked Questions

Looking for an answer to a specific question? We've collected the most frequently asked questions about Portability Check for you. 

If any questions arise while reading, you can contact us under


Frequently Asked Questions

What is a ‘Source IP Address’?

The ‘Source IP Address’ is your server’s IP address. We need it to whitelist your IP Address in our system. This is the IP address from which you’ll be able to send SMS to our server. If you don’t know your IP address, ask your IT personnel or developer.

Can I add multiple ‘Source IP Addresses’?

Yes. For each new account, you can add up to 2 new IP addresses. If you feel you need more, just get in touch with our Customer Success Team and they’ll be happy to help you.

What is the ‘Respond back URL’?

Each time our system looks up a number, it posts the requested number information to your webserver. The ‘Respond back URL’ is the URL you’d like us to send the information to.

What does the number information receipt look like?

The requested number information is provided in the body of the “HTTP 200 OK” response of tyntec’s application server. It looks like this:

“operator”:” Vodafone”,

How soon can I start using the new Portability Check account?

Instantly! You will be able to start using your Portability Check account right away after you receive the email with your credentials.

What is the difference between the RESTful API and ENUM?

ENUM is a system that unifies the international number system with the Domain Name System (DNS). As a mapping standard, ENUM uses the common Internet DNS system to translate E.164 phone number into IP addresses that can be used in internet communications.

ENUM is based on UDP communication by default, which generally means that there’s no guaranteed package delivery.

You can use either the ENUM protocol or our RESTful API to access our Portability Check or Number Verification services.

Specifics for the ENUM protocol are:

  • No requirement to transmit username or password
  • Authentication is based on your IP. We highly recommend a VPN connection to increase the security of your connection in this case.
  • No unique identifier is needed (unlike the message ID used by other tyntec services). The identification for individual queries is based on the phone number queried, the IP the query came from and the query timestamp
  • Timeout parameter: If tyntec does not get a response within a specified timeframe, you will receive an error response

If you use our RESTful API, the communication is established via Hypertext Transfer Protocol Secure (HTTPS) connections. The exchanged object type is typically a JavaScript Object Notation (JSON). tyntec’s application accepts and replies with “application/json” as “Content-Type” (and “charset=utf-8”) in the HTTP header.

How much does it cost to perform a number check?

Head to the Pricing & Coverage section for more information about prices. You can find it under ‘Finance’ in the main navigation while logged in to your tyntec account.

Where can I find the technical documentation for Portability Check?

You can find the technical documentation and how to set up Portability Check in our Tech Docs under: