Effective date of estimated tax payment made from part of refund via Turbotax?

[sparcel]

In using Turbotax desktop to eFile my returns I entered to apply part of my 2022 Fed refund toward 2023 taxes.  When will the estimated payment be considered to be applied?  a) when I submitted my eFile i.e. Pending, b) when the eFile is "Accepted", or c) when the IRS actually processes my return.

If it is "c" then if the IRS takes too long to process my return I assume the payment could be considered to be past the April 18 boundary?

[DoninGA · Accepted solution]

It is effective the day the e-filed tax return was received by the IRS regardless of when the IRS completes the processing of the tax return.