Are formal trusts required to apply for a Tax Identifiaction Number. I thought a few years ago, this went into effect, but I could certainly have misd-terpreted something I read, in which case can a grantor/trustee use his/her personal SS# for the Trust? OR if perchance, trust are supposed to get such numbers would trusts in effect prior to a speicified date be grandfathered in?

Unless it's a feature of your particular state law, trusts may use the SSN of the grantors during their lifetime. Death causes the trust to become irrevocable. Other trusts may be set up as irrevocable from the outset. Those would be ineligible for the grantor's SSN and would require an EIN.