Skip to main content
CallTower Solutions Center

CallTower Information - DID Porting Timelines And Process

For information on LOAs and Requirements, click the link below: 


CallTower’s goal is to provide the best possible porting experience to you and your organization.  CallTower has significant porting experience and is here to help guide you through the process and to help make the transition as easy as possible.  This document has been created to help you understand the process of porting numbers from your current carrier to CallTower, the documentation that will be required, the carrier-defined timelines, and the role you will play in ensuring porting is successful.  There is also information on what we can do together to eliminate or resolve some of the potential problems that may arise during the porting process.

On first thought, moving your phone numbers from provider to provider seems like a simple idea; however, the reality is that porting numbers is a complex and multi-faceted process that can have many complications involving several parties.   The Federal Communications Commission (FCC) governs the rules and responsibilities of all carriers in this process. CallTower and our carriers must comply with those regulations. For your number to port in a timely manner, the entire order must follow prescribed processes and procedures set out by the FCC and gaining/losing carriers.  

Below is a simple overview of the process, timelines, and potential pitfalls, including what must be done in each case to avoid or resolve them.





Domestic duration

International duration

Initiation, Discovery


Select RDD

CallTower will work with the Customer to create a LOA (Letter of Authority).  The LOA is the document that authorizes the port activity.  

A copy of your most recent carrier invoice dated within 30 days. If the invoice does not list all the porting numbers then a CSR is required.

CallTower and the Customer will determine what date to request the port, this is called the RDD (Requested Due Date).

These documents are required to pre-validate the port request.  The LOA is submitted along with the order to the carrier.

The LOA must be completed with information that matches the Bill and/or the CSR.  It must be signed by someone the existing carrier recognizes as an authorized company contact.

Toll-Free numbers require a separate LOA standard DID ports.

During this time CallTower will often pre-validate the portability of the Customer numbers.

To avoid problems with pushing out a due date, the RDD should be far enough in advance to allow all services to be installed and the customer to complete preparation. 



Order Submit


CallTower will gather all submission information and coordinate the order request with the appropriate teams.

1-2 Days

2-4 Days

Carrier-to-Carrier Order Submission

CallTower submits a port order to one of our partner carriers.


The partner carrier notifies the old service provider of the requested port.

The first thing the new carrier will do is validate the port request based on the LOA.  If the information on the LOA isn’t consistent with the customer records the order will be rejected.

This typically takes 3-5 days; however, depending on the carrier and the complexity of the order (e.g. over 50 DIDs), this process can take 10-15 days

3-15 Days

6-45 Days

FOC Granted,

Port Scheduled

The old service provider validates the information on the LOA and grants FOC (Firm Order Commitment) with a port date.

With the FOC granted the port is scheduled.

The FOC is the day the port is expected to take place.  

8-10 Days

10-30 Days

Port Readiness

CallTower will work with the Customer to ensure that everything is set up and ready for the port to take place.

CallTower will work with the Customer to ensure that they are ready for port date. 

Customer should confirm as quickly as possible that they will be ready for the FOC date.  

CallTower needs at least 5 business days to change a due date without causing any problems with the order. Changes to port orders may result in additional fees. 

At Least 5 Days Before Port Date

At Least 5 Days Before Port Date

Port Complete

On the FOC date the change in carrier is activated and the port is completed.

·     If it is a scheduled port, it will happen automatically. 

·     If it is a triggered port, CallTower will push the button to activate the port.

Typically, M-F 8 AM – 3 PM local time, varies by carrier. 

Day of Port

Day of Port


  • Was this article helpful?