@missjulia101 Giving a full answer would require more detail, but one thing to keep in mind is that QB does not adjust its federal and state income tax withholdings based on YTD information, unlike the social security and medicare taxes.
Because of this, it's not unusual for this kind of discrepancy to arise for most employees; since the withholdings are being calculated on a paycheck to paycheck basis, and the gross pay of most employees tends to fluctuate, it's quite possible for slow weeks to have no income tax withholding at all even as their gross pay rises.
This has to do in large part with the IRs' changes to the W4 from 2020; in short, they attempted to change it such that people break even on their income taxes, and it's caused nothing but trouble since.
If the gross wages for the pay period aren't projected to be higher than the standard deduction plus the effects of any dependents, it simply won't hold any federal income tax out on that paycheck as it doesn't expect any tax to be owed.
Anyway.
That QB representative was full of it. Don't let them stress you out.
As for what you can do, when my clients' employees ask me about this, I generally advise them to only fill out the W-4 as Single with no dependents and, if necessary, fill in an amount on the Extra Withholding line.
That being said, if the employee you mention is grossing approximately $70,000 per year, they will have $40,000 in taxable income after their $30,000 MFJ standard deduction.
The actual numbers will be lower as income taxes are stepped in brackets, but even if you were to apply the full 12% expected income tax rate to that $40,000, you'd have income tax of $4,800.
If they have held out $1,289 in Q1 2025 so far, then you'd reasonably expect them to hold out 4X that over the course of 2025, or $5,156. So, it sounds like it's not far off the mark as far as this specific employees' withholding.
It could be complicated if the husband also has income, but there's just not much QB can do about outside factors like that. They can't know what other sources of income this couple has. Maybe mark the 2 Jobs box if the couple have similar earnings throughout the year.
