The present disclosure relates to a replaceable printing component for use in a printing system including print mechanism configured to receive the replaceable printing component. The replaceable printing component includes an electrical storage device responsive to printing system control signals for selectively storing information received from the print mechanism, the electrical storage device includes a storage portion containing data associated with the replaceable printing component, and first and second validation fields configured to store error detection codes relatable to the data contained in the storage portion to determine whether the data is valid. Wherein the electrical storage device is configured, prior to a first transfer of data from the print mechanism to the storage portion, to receive and store in one of the first and second validation fields an error detection code related to the data currently contained in the storage portion, and the electrical storage device is configured to receive and store in the other of the first and second validation fields an error detection code related to the data that will be contained in the storage portion after the first data transfer.