Dear _____________
My next _______________ (specify) payment will be due on ____________ (date).
Due to an unexpected emergency that has occurred, I will be unable to make this payment by the ______________ (date). I am requesting an extension of ___________ (days) to make this payment.
If you review my file, I believe you will find that my payments have generally been made in a timely fashion. My relationship with your bank is very important to me, as well as my desire to maintain a good credit rating.
Thank you very much for your consideration of this request.