Exchange rate theory has recently been concerned with versions of the uncovered interest rate parity (UIP) condition, as an alternative to purchasing power parity. The UIP condition is examined, for the U.S. Dollar, the Deutschemark, the Yen, and the Swiss Franc all against the Pound Sterling, using dynamic specification tests based on residual from the LUS and OLS classes, and selected error orthogonality tests. Market errors for one currency may have an information role for other currencies, this also is tested. It is suggested that spot rates are determined by the same underlying process which requires a considerable amount of past information on market errors for efficient spot rate determination. A role for time varying risk premia is suggested.