Original: Introduction of ISAs ISAs were introduced on 6 April 1999 , replacing the earlier Personal Equity Plans ( PEPs ) and Tax-Exempt Special Savings Accounts ( TESSAs ) , which continued to exist only for money already invested in them and for interplan transfers .
Simplified: Before that , Personal Equity Plans ( PEPs ) and Tax-Exempt Special Savings Accounts ( TESSAs ) where used .