You must keep records and supporting documents at your establishment, your residence or any other place we designate for six years following the year they cover. If they are in an electronic or digital format, they must be kept in intelligible form on the same medium for the same amount of time. You must also take the necessary steps to ensure and maintain their integrity throughout their lifecycle.

The sales recording system (SRS) and server (or both) store billing data. You must ensure that data is retained by regularly making paper or electronic backup copies of transaction data such as bills and supporting documents for adjusted and cancelled transactions.