We hereby inform you that the receipt of your car insurance is now available for payment, which may be done through the means listed on the back. In order to maintain the regularity of contractual warranties, we remind you that you ought to provide the settlement by the deadline. We thank you for choosing our company and remain at your disposal. Yours sincerely,
Posljednji potvrdio i uredio lilian canale - 7 kolovoz 2008 14:54
- 'now' for 'already'. Less literal but more commonly used in English
- 'we remind you that you should provide...'
- 'we thank you for choosing our company'
I've taken into consideration most of your suggestions, but I'd rather keep "ought to" instead of changing for "should", because the former expresses better a mandatory behaviour.