As soon as the tax law changed, Uncle Sam elected to change the withholding tables, reducing the federal tax withheld from salaries and wages. So you may have seen an instant increase in your pay check.

However, this means that while you probably owe less tax in 2018 on the same earnings as in 2017, you will have had less federal tax withheld during the year.

And yes, that could mean less or no increase in your tax refund.