If you recently started working two jobs, filling out your W-4 forms correctly is essential to ensure the right amount of tax is withheld from your paychecks. Each employer withholds taxes based on your earnings from that job alone, so you must coordinate your W-4s to reflect your total income and avoid owing taxes or receiving a large refund. Following IRS guidelines and using their Tax Withholding Estimator can help you fill out your W-4s accurately for both jobs.
Why filling out your W-4 correctly matters when you have two jobs
Each employer calculates withholding based only on the income you earn from that job. If both employers withhold as if their paycheck is your only income, you could end up under-withholding overall. This means you might owe taxes and possibly penalties when you file. Conversely, if you claim too few allowances or don't adjust your W-4, you risk having too much tax withheld, resulting in a large refund but less take-home pay during the year. Properly completing your W-4 lets the combined withholding from both jobs better match your actual tax liability, balancing your cash flow and tax responsibilities.
How to use the IRS Tax Withholding Estimator for two jobs
The IRS Tax Withholding Estimator helps you calculate the correct withholding amount by considering all your income sources together. To use it for two jobs:
- Gather recent pay stubs from both jobs and your most recent tax return if available.
- Go to the IRS Tax Withholding Estimator on the IRS website.
- Enter your filing status and information about dependents.
- Provide income details for both jobs, including pay frequency and year-to-date earnings.
- Include any other income, deductions, or tax credits.
- Review the estimator’s recommendations for withholding amounts.
The estimator accounts for your combined income, which makes its recommendations more accurate than filling out each W-4 separately without considering the other job.
Choosing which job’s W-4 to adjust and how to fill it out
The IRS recommends treating your highest paying job as your primary job for withholding purposes. On that job’s W-4 form, complete Step 2 to indicate you have multiple jobs. Use the estimator’s results to decide if you need to enter any additional withholding.
For your primary job’s W-4:
- Complete Steps 1 and 5 as usual.
- In Step 2, check the box for multiple jobs or use the estimator’s worksheet to enter an additional amount to withhold.
For your second job’s W-4:
- Leave Step 2 blank.
- Fill out the form normally without requesting extra withholding.
This method prevents both employers from withholding as if each job were your sole income, avoiding excessive withholding. Alternatively, you can increase the extra withholding amount on one W-4 to cover your combined tax liability.
What to do if both employers require separate W-4 forms
When both employers require W-4 forms, you need to coordinate the withholding to avoid mistakes.
For your higher paying job, complete the W-4 including Step 2 for multiple jobs and add any additional withholding recommended by the estimator.
For your second job, fill out the W-4 as if it were your only job but do not check Step 2 for multiple jobs. You can enter zero for extra withholding here.
This balances withholding between jobs. If you claim multiple jobs on both forms or add extra withholding on both without coordination, you risk withholding too much. If neither form reflects multiple jobs, you risk under-withholding.
You can also ask your second employer to withhold an extra fixed amount per paycheck to cover combined taxes, but using Step 2 on your primary job’s W-4 usually yields a more accurate result.
Common mistakes to avoid when filling out multiple W-4s
A common mistake is claiming too many allowances or exemptions on both W-4s to increase take-home pay, which often leads to under-withholding and tax bills at filing.
Another error is neglecting that you have two jobs and filling out each W-4 as if it were your only source of income. This causes both employers to withhold too little combined, resulting in taxes owed.
Forgetting to update your W-4 when your second job starts or ends mid-year can also disrupt withholding accuracy.
For example, if you have two jobs each paying $30,000 annually and both employers withhold taxes assuming that’s your only income, you might owe hundreds because of under-withholding. Adjusting the higher paying job’s W-4 for multiple jobs improves withholding accuracy.
Avoid using old W-4 forms from before 2020, since the IRS redesigned the form to better handle multiple jobs and other tax situations.
When to update your W-4 if your jobs or income change
Update your W-4 whenever your employment or income changes. This includes:
- Starting or ending a second job.
- Significant pay increases or decreases.
- Changes to your filing status or number of dependents.
- Life events like marriage or having a child that affect tax credits.
Updating your W-4 promptly keeps your withholding aligned with your tax liability, reducing the chance of owing money or receiving an unexpectedly large refund.
To update, use the IRS Tax Withholding Estimator with your new income details and fill out a new W-4 based on its recommendations. Submit the updated form to your employer(s) as soon as possible so withholding adjusts for the rest of the year.
Conclusion
Handling tax withholding when you have two jobs requires some coordination but is straightforward if you follow the right steps. Designate your highest paying job as primary and complete its W-4 with the multiple jobs adjustment. Use the IRS Tax Withholding Estimator to guide your entries and adjust withholding amounts as needed. Keep your W-4s updated whenever your income or job situation changes. This approach helps you avoid surprises at tax time and manage your paycheck effectively throughout the year.
Frequently Asked Questions
Can I just split my allowances between both jobs on the W-4 forms?
No. Splitting allowances without considering your total income usually causes under-withholding. It's better to designate one job as your primary and use the IRS estimator to set withholding correctly.
What happens if I don’t fill out a W-4 for my second job?
If you don't submit a W-4 to your second employer, they will likely withhold taxes at the highest rate, which can lead to too much tax being taken out and reduce your take-home pay unnecessarily.
Is it okay to request extra withholding on one job to cover taxes from both?
Yes, asking one employer to withhold an additional flat amount to cover your combined tax liability is allowed. However, using Step 2 on your primary job’s W-4 generally provides a more accurate withholding adjustment.