If you are on a plan with subacounts, you can easily move tracking numbers between those accounts as needed.
Go to >>
Click All Accounts button in upper right.
You will see the account for each tracking number listed in the now red/pink column. Click change account below the account name and you can choose from any of your existing sub-accounts to move the number to.
(*If the sub-account doesn't exist yet in the dropdown, you will need to create it by going to Settings>>Accounts, click add new account button in upper right.*)
Clicking the change account link you will then be able to select a different account from the dropdown of all the accounts in your Agency. Once you have selected the new account click the button.
After you press the change account button you will get a new window that looks like the following:
This tells you the number you are moving and the new account you just selected.
*It will remember the current receiving number which you can change if you wish and the current tracking source, which you can change.*
Click the Move call data with number box to move the numbers data to the new account.
Then press Move Number to complete the move.