For your primary job with the highest income, you should have the W4 exemptions match your filing status and dependents claimed. For example, if you are married filing joint and have 1 dependent, list 3. However, for your second job, list 0, so that the maximum amount is deducted.
This helps ensure that the correct amount of tax is deducted, when the income from your second job is combined with your primary job. Do you know where to enter on W4?
