_________ (Customer’s Name),
_________ (Customer’s Address)

Date: __/__/____ (Date),

Subject: Notification of New Telephone Number

Dear Valued Customer,

We would like to inform you that our telephone number has been updated to better serve your needs. The new contact number is _________. Please make a note of this change for future communications.

Thank you for your understanding, and we look forward to continuing our excellent service to you.

Thank you for your cooperation.

_________ (Your Signature)
_________ (Your Name)
_________ (Contact number)