MIP Documentation

What MIP documentation are you required to maintain, and how do you do this (paper or electronic) in order to establish compliance with your MIP policies/procedures? Currently we maintain all printed documents, which include the eFunds/Qualifile check and the printed OFAC inquiry. These items are then attached to the original signature card and filed. At the present time, we scan member identification and our signature cards, but not the other MIP docs. Due to space constraints we are looking to shred the sig cards after scanning and QC, however are looking for guidance on the other required MIP documentation. If you maintain them in paper form, for how long? Or, if you don't due to other audit trails (i.e. electonic audit trail), how do the regulators or external auditors view this? Thanks for your help! - Kathie