Note that there is a mandatory 20% tax withholding required on 401(k) distributions reguardless if you pay estimated tax or not.
You can make estimated tax payments using a 1040ES form or just make the payments online at: https://www.irs.gov/payments.
But note that if you expect the tax to be more than the mandatory 20% tax withholding on 401(k) distributions and/or if you are also subject to the additional 10% penalty then it is usually better to just have the 401(k) plan administrator withhold more. For example if you expect to be in the 26% tax bracket and are under age 59 1/2 then having 35% or more withheld would make estimated payments unnecessary.
Estimated tax payments for lump sum payments usually require using a 2210 form with your tax return to show the unequal income while tax withholding does not require that and is simpler.
The tax would be the same either way.
Also see:
https://www.irs.gov/newsroom/five-tax-tips-on-making-estimated-tax-payments
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
