Hi,
I suggest you to take imitative to prepare such communications by your own for 2 reasons. Number one it will improve your writing skills. Number two you alone will know background of the circular rather than all the members of this forum. So you will be able come out better draft. Any how just refer the following and edit as per your requirement :
Dear Employees,
As you all aware currently our Company is reimbursing eligible employees for necessary expenses incurred towards approved work-related travel. Now with effect from ______ it has been decided to amend the Travel Policy as below :
W.e.f _____ any employee travelling beyond 150 kms should submit proper / original fuel receipt when applying for reimbursement. The original bill along with reimbursement form should be submitted to Accounts Dept within ___days from the date of travel. The travel reimbursement form must be signed by the Authority who approves the official travel. Travel reimbursement form without supporting original fuel bill will not be entertained strictly.
All your co-operation is solicited.
Regards
HR Dept