PSA: Multiple Jobs block on W4 form

[Vette40th]

After noticing a change in my taxes after a life change, I went to make sure my W4 at work was correct to reflect it.
I noticed a multiple jobs box on the W4 form. This came out in 2020. Our company has a mock test to see what happens when you adjust the W4.
Just by clicking this my Federal, and only Federal, taxes increased 25%. Nothing other than checking that box.
I am retired, so I owe regardless if I don't adjust somewhere in my withholdings, W4 or just transfer to savings all year till I have to do taxes.
I make good money, with my retirement.. Not paycheck to paycheck..
I know the tax laws were changed a few years ago to have the government take out less per year, so you had more in pocket during the year. This resulted in less refund.. Which is good.
But last year my taxes owed to IRS went up 25%. My pay barely changed last year prior to it. So, it would seem I had more money coming in last year, than the year prior to.
And, I am claiming single, zero on retirement and my regular job. Mortgage interest was my only itemize item, but it wasnt enough to cover a standard deduction.

[Mike Mercury]

https://taxsharkinc.com/fill-out-w4-second-job/

since you're retired, the point is moot.

But... if you were working two jobs, it would often kick you up a tax bracket (both incomes combined) ; although each job - singularly - would be in the lower tax bracket.

Checking the multiple job box increases your witholding so that at the end of the year your fed taxes burdon is somewhat met (you would not owe a large sum due to the tax bracket jump).

[Vette40th]

I am retired, and I can withhold more at DFAS/MyPay.. But this little box is another way to have more money taken out, as you stated. Therefore you burden at the end of the year is lessened. Mine comes out to about 25%... And there is nothing more to do. Just check the box..