The W‑4 Step Most Taxpayers Skip — And Why It’s Causing Surprise Tax Bills
The Multiple Jobs Worksheet on Form W-4 is one of the most overlooked sections – and skipping it is a major reason taxpayers end up with unexpected balances due. When this worksheet is not completed, the IRS assumes you have only one job, which almost always results in under-withholding if you or your spouse works more than one job at the same time.
Why the W-4 Exists
The W-4 tells your employer how much federal income tax to withhold from each paycheck. The IRS withholding tables are built on a simple assumption: one job, one income stream.
But that assumption breaks down fast when a household has multiple jobs. Income from each job stacks together, pushing you into a higher tax bracket. If the W-4 isn’t adjusted using the Multiple Jobs Worksheet, each employer withholds too little – because they think their job is your job.
Why the Multiple Jobs Worksheet Matters
Multiple job income increases your tax bracket, but employers don’t know that unless you tell them.
Accurate withholding depends on accounting for all jobs in the household.
IRS rules require adjustments when more than one job exists.
Prevents balance dues by ensuring enough tax is withheld throughout the year.
Most clients who owe unexpectedly at tax time have one thing in common: They did not complete the Multiple Jobs Worksheet.
What Happens If You Skip the Worksheet
You should complete the Multiple Jobs Worksheet if:
You have two or more jobs at the same time
You and your spouse both work
You start a second job mid-year
You have a side W-2 job in addition to your main job
If you’re unsure, it’s safer to assume you should complete it.
Note: if you and your spouse together have two jobs with similar pay, you can instead check the box in Step 2(c) — simpler, but it withholds at a flat higher rate rather than a precisely calculated one. The Multiple Jobs Worksheet gives a more accurate number and is the better option once pay is uneven or there are more than two jobs.
How the Worksheet Works
The worksheet helps you:
Add up all jobs to estimate total household income.
Determine the correct tax bracket for that combined income.
Calculate extra withholding needed per paycheck.
You then enter the additional withholding amount on Step 4(c) of your W-4.
A Simple Example
A married couple both work:
Taxpayer earns $120,000
Spouse earns $80,000
Each employer withholds as if the taxpayer earns only their job’s income. But the IRS taxes them on $200,000 total.
Without the multiple jobs worksheet, the taxpayer is under-withholding all year and ends up owing.
How We Can Help
As your tax advisor, we can:
Review your W-4 for accuracy
Help you complete the Multiple Jobs Worksheet
Estimate your annual tax liability
Recommend the correct additional withholding amount
Prevent surprises at tax time
If you’d like us to review your W-4 or help you complete the worksheet, please feel free to contact our office at (480) 732-9898 or admin@vogttax.com.
This post is for general informational purposes only and does not constitute tax, legal, or financial advice. Withholding needs vary by individual circumstances. Consult a qualified tax professional before making changes to your Form W-4.
