商务英语写作范文:要求付款，并付上新发票

Dear Sirs,

　　We have received your letter of March 2 with thanks.

　　As requested,we are enclosing a fresh invoice for our services offered on　August? 25,2006,previously billed under our invoice No.829,which you could not find.

　　Since the account is long overdue,we would very much appreciate your prompt processing of payment on your side.?　　

　　Yours faithfully,