Most business hold on to records for a certain period either because they are obligated to by statutes or ethical cannons (attorneys and doctors are a good example) but most do so for tax purposes. Another reason that a party would keep the records are fear of litigation.  So after the statute of limitations has expired for such litigation in your area then arguably you can throw the records out (or shred them really if there is personal information contained in them).  But a prudent landlord will keep a history on the rental unit in some form forever either on ledger cards or on a computer disc.  Check what the statute is for suits based upon a rental contract is in your area.  Keep them at least that long.