There are several steps you can take now to avoid surprises.
You should take steps now to avoid owing more taxes or getting a larger refund than you expect in 2015. The US Federal Tax System is a "pay-as-you-go" system. That means that the IRS expects tax payments throughout the year as income is received. Your annual tax return is a recap and reconciliation of the past year.
As we start the 2015 tax year with the ringing of the bells and the blast of fireworks at midnight on January 1, the following are some actions you can take to bring the taxes you pay in advance closer to what you'll owe when you file your tax return:
Adjust your withholding
If you're an employee and you think that your tax withholding will fall short of your total 2014 tax liability, you may consider increasing your withholding. If you are having too much tax taken out of your paycheck, you can reduce your withholding. To change your withholding at any time during the year, complete a new Form W-4, Employee's Withholding Allowance Certificate, and give it to your employer. To increase your withholding enter the additional amount you want withheld from each paycheck until the end of the year on Line 6 of the W-4 form. You usually can have less tax withheld by increasing your withholding allowances on line 5. Use the IRS Withholding Calculator tool on IRS.gov to help you fill out the form.
Pay estimated tax by the due date
If you receive income that's not subject to withholding you may need to pay estimated tax. This may include income such as self-employment, interest, or rent. If you expect to owe $1,000 or more in tax, and meet other conditions, you may need to pay this tax. The tax is usually paid four times a year. Use Form 1040-ES, Estimated Tax for Individuals, to figure and pay the tax. Even if you pay your estimated tax, if you do not "pay as you go" and miss payment deadlines, you could be charged penalties or interest.
Update your taxes with life events
You may need to change the taxes you pay when certain life events take place. A change in your marital status, the purchase of a house, or the birth of a child can change the amount of taxes you owe. When these events occur, make sure you make adjustments to your tax withholding or your estimated tax payments.