Government uses Treasury bill as a form raising money on a debt form. a minimum face value (capital) is needed to secure a 91,182 or 364 maturity bill. the returns is usually assured at the end of the maturity of the bill. you get back your face value and interest as well. official website for central bank is www.centralbank.go.ke. my contacts is 0114456187 email mugonderitu@gmail.com.