I assume that sending copies of "Account Ledgers" is common practice in business there. Here, we would write something like
Dear Mr XXX
Our records show that there is an outstanding payment on your account of £126.25 (Invoice number 274612 dated 4/1/2013 refers). Please make payment immediately. If you believe you have paid this invoice, please send us a copy of the receipt for payment.
Student or Learner