A “TIN” (Taxpayer Identification Number) is a number created through the IRS to track specific accounts and ventures for ease of tax reporting.
Acquiring a TIN is a personal decision/preference for tax reporting. (The decision may be affected by your bank’s account requirements; you should check with them regarding their trust account policies).
There is no legal requirement per se for obtaining a TIN for a Living Trust or its accounts in most instances.
Details on Standard Legal’s Living Trust legal forms software is here.