The Zoom Support team can investigate and recover accidentally deleted or previously owned phone numbers you want back.
To recover a deleted phone number, contact Zoom Support. Include your Zoom Phone account number and the numbers you want to recover, with a brief explanation of how the numbers were removed from your account (for example, they were deleted by accident or removed as not needed).
Note: Once a number is removed or deleted from your account, it will be made available to other Zoom customers after 30 days. To avoid this, when changing your main company number, you can choose to replace the number while keeping the old main company number.