Prep Smartz Academy Article

There are times, especially during an emergency, when you need to contact a group of people on short notice.  In those situations, you typically need to contact them quickly.  Creating a call tree can be useful in spreading the burden of contacting everyone.

A call tree is a method where the initiator calls a few people and they call a few people until everyone has been called.  Most call trees are one directional.  They flow from the initiator.  To ensure that everyone has been contacted, a call tree can be created to include reporting the status to the initiator.  This allows the initiator to know who has been contacted and who wasn’t contacted.  If done correctly, you can notify thirty people within a couple minutes. 

Steps to create a call tree

  1. Determine this initiator.
    This is the person at the top of the tree. More information about the initiator role is included below.
  2. Determine the first-level branch
    A link to a tree example is provided at the end of this article
  3. Determine the lower-level branches
  4. Collect the phone numbers
  5. Test the call tree
    More information about the testing is included below.
  6. Make adjustments as a result of the tests
  7. Revise the call tree as people leave the call group
    Call trees are fluid. Stay current with changes and test each version

Who should create a call tree?

Call trees are used by volunteer emergency responders, youth group leaders, church groups, work groups and more. A call tree is also useful for family members to communicate during an emergency.  You don’t need an emergency to benefit from a call tree. They are useful when plans for the family reunion changes at the last minute or a meeting needs to be canceled on short notice.  Call tree examples include:

  • Our family belonged to an astronomy club in the Midwest (USA).  Occasionally we could see the aurora borealis. The club had a call tree for aurora.  Most of the 350 people in the club were on the call list.  When the aurora was visible, everyone were alerted quickly.
  • In areas where weather can affect the work day, offices use call trees to advise employees not to go to work. You don’t want to miss that call!
  • Emergency service volunteers are usually proficient in using call trees to muster response teams.

Who should be on the call tree?

A call tree needs to have an initiator.  This is the pivotal person.  The initiator needs to understand their role and accept the responsibility.  They will decide if the call tree should be used.  The initiator coordinates call tree tests and maintains the call tree.

The branches are filled with people that have a common interest and have a need to communicate a short message, by phone.

How is the call tree initiated?

The triggers for initiating the call tree are determined by the initiator, with collaboration of the people on the call tree branches.  Triggers may need to be modified as the tree is tested and used.  Things that seemed to be good triggers, may become an annoyance.  I was on a weather-related call tree.  Most of the time, the weather event didn’t affect me.  In the astronomy example above, the members may want to put a time limit on activating the call tree.  They could decide not to initiate the call tree after 3:00 AM.

Emergencies can happen at any time.  This can include call trees at your job or school.

What should you say in your message?

This isn’t the time to trade chicken casserole recipes. A best practice is to announce, “This is a phone alert message.” Then proceed with the relevant information.

  • The situation is…
  • The expected duration is …
  • My call back number is…
  • The instructions are…

It is important to relay the exact message then say goodbye. The objective is to pass the accurate message down the call tree as quickly as possible.

What if you don’t make contact?

If you are unable to contact the person that you are assigned to call, leave a message if possible.  Go to the next person on your branch.  Keep going down the branch until you reach someone.  When you reach someone (on your branch) pass along the people who haven’t been contacted.  The last call on each branch is the person at the root of the branch.

Everyone on the call tree needs to keep a current copy of the call tree easily accessible.

How do you report status?

The call tree explained in this article includes a feedback flow.  The last person on each branch calls the person at the root of the branch to provide a status of who was contacted and who was not contacted.  Like the message flowing down (the call tree), the status messages need to be brief.  Only report the people who were not contacted.  The initiator should receive the call penetration status within a couple of minutes from the first call.

Why you need to test the call tree?

Testing reveals weak links in the call tree.  It is beneficial to identify and correct deficiencies before you really need to use the call tree.  During emergency situations, succinct and accurate communication is paramount.  When you test the call tree, follow the same protocol as an actual call tree message.  When testing the call tree, begin your call with “This is a test phone alert message.”  Then proceed with the test message.

The initiator measures the duration of the call tree.  It begins when the initiator calls the first person and ends when the initiator receives the last status.  The test includes checking the accuracy of the message. That means, the message that was initiated is the same from the last status report.

A memorable call, for me, was when there was an active shooter at my office campus.  The call was initiated early in the morning, to notify employees to stay away from the area.  In this case, the call tree was not effective.  To be effective, call trees need to be tested/practiced and maintained.

Is a call tree just for phones?

Most call trees are designed for telephones.  Radios can be used for call trees.  They can be effective in a situation when phone service in unavailable.  Because radio transmission ranges can be limited, geographical placement is a factor in creating a radio call tree.  The call tree will need to consider the location of each person on the branch.  Each person (on a branch) will need to be able to reach then next person on the branch. 

The feedback flow is also a consideration.  If the last person on the branch cannot reach the person at the root, they will need to provide feedback throw the branch in reverse order.  That situation will take a little more time to complete the call tree, but the initiator would be able to receive a status.

Another consideration for radio call trees is atmospheric and topographical conditions. They can affect the range of radio transmissions.  In some situations, a transmission will need to be attempted at a later time or from an alternative location.

Radio transmissions can be heard by anyone else who is tuned to the same frequency.  If you broadcast that you are leaving your house, looters could use that information to target your belongings.  Most radio operators use call signs to mask their identities.  They only reveal their name to trusted people. 

Radio operators also use prowords to reduce the transmission length and mask the message.  You may want to establish a proword to send police to your house.  The proword could be “big stick”.  If you need police, you could transmit that you need a “big stick” at “Whispering Meadow”.  In that example “Whispering Meadow” is a proword for your home.  Someone on your call tree would know that you need police at your home.

Call tree example and template

The link below is an example of a call tree.  It can be used as a template for creating a call tree with a feedback flow.  The template is a Microsoft Word document.  Just add the names and contact information to the template.  When you complete the template, send a copy to everyone on the call tree.  It’s important to test the call tree and maintain it.  When people are changed, send everyone a revised copy and test the change.


Call tree example and template


roger eatonBy Roger Eaton

Over thirty years of experience in information technology and over seventeen years of experience in emergency services converged to inspire Eaton to develop Prep Smartz, emergency management software and Prep Smartz Academy.


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