Why am I getting a allocated portion of my 2024 refund credited to my Schedule A deductions?

[MRinSC]

I have found similar questions but not exact to my situation.  In 2024 I made a 4th qtr state (SC) tax payment of $7000.  I entered it in 2024 TT as a 4th quarter payment made on 1/15/2025.  This rolled up with my state withholdings to give a total taxes paid in for 2024 of $35,209 including the 4th qtr estimated payment.   Due to an employer error I ended up with a large refund of $7902 paid in 2025.  On the State and Local Income Tax Refund Worksheet Sch 1 Line 1 2025, in Part 1, line 1 it shows (b) the correct 2024 refund amount of $7902, it shows the correct Estimated Tax Paid after 12/31/2024 (c) of $7000, it shows Total Payments and Witholdings (e) of $35,209  which is correct and finally, it shows Refund Allocated to Column (C) in column (f) of $1571.  

I can't tie the $1571 number back to anything so I don't know how it is calculated.  More importantly, the $1571 appears on line 3 as a portion of the refund allocated to tax paid after 12/31/2024 which flows to Sch A line 5a.  It seems like I am double dipping on the credit.  I don't understand why the Line 1 (c) "
Estimated tax paid after 12/31/2024" is impacting 2025?  Is there a credit due on $902 ($7902 refund - $7000 est. tax pmt) of real taxes paid in 2025 that were not itemized in 2024?

[MRinSC]

Sorry, I left out a key part of my question.  On the worksheet for Sch A, line 5 it shows my 2025 state income tax withheld on Line 1, ~15k, it shows on line 3 $7000 for 2024 state estimated taxes paid in 2025.  These two total to give me a ~$22k deduction minus the $1571 mentioned earlier for a deduction of ~$21k for 2025 for state income tax.  The $7000 of 4th qtr taxes paid on 1/15/25 is included in this total.  This is where it feels like a double dip.  I credited this to my 2024 taxes paid and now it looks like it is added to my 2025 taxes paid (minus the $1571).  It does not seem right to get a credit for the $7000 twice.

[ThomasM125 · Accepted solution]

On your federal return, you can deduct the state taxes in the year they are paid even if they get applied to the state tax obligation of the previous year. Applying your $7,000 state tax paid in 2025 to your 2024 state tax return has no affect on the itemized deductions reported on your federal return in 2024. The federal itemized tax deduction is simply the state taxes paid that year, regardless of what your actual state tax obligation is for that year.