For most Revocable Living Trusts, a separate tax identification number — often called an Employer Identification Number (EIN) — is not required while the Grantor is alive.
A Revocable Living Trust is not considered a separate taxable entity during the Grantor’s lifetime. There are, however, some situations where a living trust would apply for a tax ID number, but these situations are generally not common.
United States Tax ID numbers can be obtained from the IRS, using the IRS online portal here >.
Of course, a person should seek the advice of an attorney or accountant if you questions exist or on issues specific to more complex Trust or Estate Planning.