Death of a Tax Payer and a living revocable trust

A tax payer dies on June 1, 2023 with income producing stocks and bonds inside a living revocable trust. Before the tax payer dies, the trust was reporting the income under the tax payer Social Security number. The money is going to the tax payer's son, possible in trust.

 

What tax id should the  income received after June 1, 2023 in the living revocable trust be reported to the IRS under? I am thinking it would either by the son's Social Security number or the EIN of the estate. If it  is reported under the wrong tax id is it a big deal?