Reminder letters are normally regarding outstanding accounts, but are sometimes related to other matters requiring the addressee to perform some action.
It's usual to use a Delinquent Account letter as the last resort prior to taking action.
Do NOT use a Delinquent Account type of letter as your only method of dealing with issues of this kind.
It can antagonize clients who simply didn't remember to take action, and alienate good customers.
Reminder letters are much less demanding, but are intended to get the recipient to take appropriate action.
Reminder regarding outstanding account ($…., for item name)
Please be advised that monies owing on the above account are now payable.
Our terms of service permit a calendar month from the date of delivery for payment of accounts.
This period has now expired, and you are requested to finalize payment at your earliest convenience. If you have already paid this account, please disregard this notice.
If you have any queries, please contact me on the above phone number.Signed