This document contains part I of the technical specifications for the preparatory phase of Solvency II. It provides guidance on valuation of assets and liabilities, calculation of technical provisions, and the standard formula for the Solvency Capital Requirement (SCR). A number of simplifications have been included to facilitate the preparatory phase. The specifications are based on Directive 138/2009/EC, Delegated Acts, and Level 3 Guidelines available at the time. It is to be used together with part II of the technical specifications.