  We derive a closed-form formula for computing bond prices between coupon
payments. Our results cover both the `Treasury' and the `Street' pricing
methods used by sovereign and corporate issuers. We apply our formulas to two
UK gilts, the 8% Treasury Gilt 2015, and the 0.5% Treasury Gilt 2022, and show
that we can obtain the dirty price of these bonds at any date with a minimum of
calculations, and without intensive computational resources.
