Publication 15

Publication 15 also known as circular E contains the tax tables employers need to figure out how much tax has to be taken out of each employee’s paycheck.

This IRS publication contains most of the laws employers need to comply with government payroll statues. It has many examples and clarifications of law as well as the tables.

https://accounting.uworld.com/cpa-review/lc/accounting-dictionary/term/publication-15/