How to pay tax on after-death Social Security payment obtained using SSA-1724

I’m executor of my uncle’s estate. He had no surviving spouse, child, or parent.

He died in September before his August Social Security benefit was received.

To obtain the August payment on behalf of the estate, I must submit Form SSA-1724.

On the form, I added my name & address as executor.

For direct deposit, I added the estate bank account.

My understanding is that:

—  payment will be issued in name of Estate of John Doe

—  payment will be regarded as “income in respect of a decedent” (IRD)

—  IRD income is normally taxable to the estate.

What confuses me is that Form SSA-1724 does not ask for taxpayer ID number of estate (EIN). It only asks for uncle’s Social Security number.

I know that tax on the payment must be paid. But I don’t understand whether the tax gets paid on uncle’s 1040 return, or on estate’s 1041 tax return.

QUESTIONS:

(1)  Will the after-death payment be included on uncle’s SSA-1099 received in January? 

(2)  If yes, does the final payment get its own 1099 form?  Or will only one 1099 be issued that includes Social Security payments received before and after death?

(2)  If the final payment appears on uncle’s 1099, should I report the payment on his 1040 return and pay tax on it, and then disregard the payment on the estate’s 1041 return? 

.