✔ 最佳答案
To whom it may concern
Dear Sir/Madam,
This is to certify that Mr. XXX is an employee with our company with good standing since 2 Jan 2007. His current position is Technician Level 2.
If you have further questions, feel free to contact me at the above number.
Sincerely,
XXXXXX
Human Resources Manager
ABC Company
Usually the letter head has company information. You don't need to repeat the telephone number.