Job Taxes

Also, I got married in September 2024.  Since my wife did not work that year, I still filed single.  In 2025, my wife started working in March (or April) of that year, full-time.  I worked full-time and also had a part-time job averaging about 16 to 20 hours per week.  Both my wife and I filed married, but we both claimed 0 as we have no children together and no dependents, other than one another.

Both our jobs were taking out very small amounts of taxes for federal.  Her job was taking something like $50.00 or less per paycheck, for federal taxes, even though she grosses close to $1,300 per paycheck (bi-weekly).  When she asked her company about this, they said that per her filing (married, filing jointly), they are taking out the right amount of federal taxes for her.  We did not believe this, so she requested that her employer take out more for federal taxes; I think $50 to $60 dollars more per paycheck.

With me, starting with my part-time employer, I requested that they take more federal taxes out of my check, even though I that was just a part-time job, grossing about $400 per paycheck (bi-weekly).  I requested that they take out $50.00 extra per paycheck.  With my full-time job, I gross a little over $2,000 per paycheck (bi-weekly) and this job was only taking out something like a little over $38 dollars for federal taxes.  I did not think this was correct, so when I asked my employer about it, I got the same mumbo-jumbo that my wife's job gave her: based off what you put on your W4, married filing jointly with no dependents, this is the amount that we show should be taken out of your paycheck for federal taxes.  I asked again and a third time, and was told the same thing each time, so I decided to 'trust' what my employer said.

Well, when we filed our taxes for 2025, we ended up owing over $1,300 in federal taxes!  We just do not get it.  And, we filed as we stated on our W4's, married, filing jointly, no dependents.  To try and not let what happened last year happened again, I requested that my job take an additional $150 in federal taxes from my paycheck, per paycheck (bi-weekly).  This makes my checks a lot lighter, but I am just so afraid (my wife and I both are) that we will end up owing money for federal taxes again, and so we question if what our jobs are doing in their calculating is really correct or not?  Or, if it is something, or some things, we are missing with filing.  Please help.

Thank you.