Microsoft 365 Business Voice: Number Porting Best Practices
Published Mar 29 2021 12:00 AM 11.4K Views

Microsoft 365 Business Voice makes it easy for small and medium organizations to turn Microsoft Teams into a powerful and flexible telephone system. If you already have phone numbers that you would like transfer to Business Voice, you can bring them with you by porting them from your previous service provider to Microsoft. 

Porting your existing phone numbers to Microsoft 365 Business Voice can be a simple and straightforward process. To minimize potential issues, it is important to avoid common mistakes when submitting your porting requests. 
This document provides a summary of how our porting process works and includes additional guidance and resources to assist you in completing your porting requests most efficiently.

Let’s quickly look at the porting process on a high level:

  • In a nutshell, the gaining carrier (the phone service provider that you want to port your numbers to, i.e., Microsoft) raises a port request on your behalf (the end customer) and sends it to the losing carrier (the phone service provider that currently owns the phone numbers that you are trying to port).
  • The losing carrier will process the port request and respond with either an approval or a rejection. Microsoft has no say in this decision and cannot influence the behavior of the losing carrier, as it is based on completion and accuracy of the port request data.
  • When placing a port request, you will be asked to choose a target porting date and time. Choosing a target date does not mean that the port will happen on that date – the port will only occur on the target date IF the losing carrier provides approval to allow your numbers to be ported away from their system on the date that you have asked for.
  • Microsoft takes your request and submits it to the losing carrier and then relays their response back to you.

Below are a few best practices that would make your number porting process as smooth as possible:

Creating a Number Porting Request

If you are in a supported region for the automated number porting process through Teams Admin Center, we strongly recommend you to use this method.   You’ll benefit from an automated process and a structured wizard with additional guidance.

When your specific porting request (or request for new phone numbers) is not supported by the Wizard in Teams Admin Center, it needs a manual port request via e-mail.  Please use the aliases as defined in the PSTN Service Desk contact information article.

The following rules are important to be aware of when creating porting requests:

  • Request to schedule the execution of your ports during business hours in your time zone. 
  • Avoid requesting to schedule the execution of number ports on Friday afternoon because it will limit our staff’s ability to connect with the losing carrier (if necessary).  This may result in the numbers being out of service over the weekend.
  • Submit one order per each account number from the losing carrier.  Phone numbers from different account numbers in a single port order will fail. 
  • Careful planning is necessary to properly schedule the port order. Submitting multiple orders for the same carrier and account number may fail as the losing carrier may only accept one at a time.  
  • Toll-free phone numbers must be submitted on separate port orders.
  • All phone numbers in a port order must be from the same carrier.


Validate Information you provide in a porting request.

The success of your port request depends on the accuracy of the information that you provide to Microsoft when you create it.  Please validate the information accuracy with the existing provider before submitting the port request.  You can do this by obtaining a Customer Service Record (U.S.), Equipment Record (Canada), or pre-order validation bill from the current carrier.

Do not cancel existing services until porting is complete.

Your customer should not cancel their existing services with the current carrier until the number port has been completed. Number porting occurs based on account information and if you cancel your subscription, it will not succeed.

Porting different number types

Phone numbers in Business Voice can have two types: user phone numbers that can be assigned to users and service numbers that can be assigned to services such as Call Queues. 

When the phone numbers to be ported contain both user and service numbers, it is recommended to create a single port request towards Microsoft for all numbers set as user numbers. After the number port is approved (but not yet executed), you can contact the service desk and ask for an “Inventory Type Change” where you list the numbers that you’d like to change to service Numbers. In this model, the Service Desk can than schedule the inventory change right after the number port has been completed.

In addition to the above guidance, Microsoft is taking the following steps to improve the number porting experience:

  • We’re investing in additional step-by-step guidance documentation to assist customers and partners in submitting port requests.  This blog post is the first step in this direction and we will be providing more details as new resources become available.
  • The porting process is being streamlined, with new automation being added this month to accelerate response times.
  • We continue to add more staff to our number porting team to improve the experience with number porting management.


For more details and additional tips and tricks on number porting, please refer to the Number Porting - Best Practices Webinar and additional resources below:

  • What is a port order. For an overview of what number porting is and answers frequently asked questions about number porting.
  • Transferring phone numbers common questions. It includes regional support information, numbers that can and cannot be transferred, and the data required to complete the process.
  • Use the Teams Admin Center to submit a port order:
  • How to check the status of your port orders: In Teams Admin Center, use the left and go to > Voice > Port orders. Then click Order history. Each port order status is listed in the Status column.
  • Manage phone numbers for your organization and obtain LOA templates: Manage phone numbers for your organization

































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‎Apr 05 2021 10:40 AM