When it comes to filing a federal tax return, many people discover that they either get a larger refund or owe more tax than they expected. But this type of tax surprise doesn’t have to happen to you. One way to prevent it is to change the amount of tax withheld from your wages. You can also change the amount of estimated tax you pay. Here are some tips to help you bring the amount of tax that you pay in during the year closer to what you’ll actually owe:

• New Job.   When you start a new job, you must fill out a Form W-4, Employee’s Withholding Allowance Certificate. Your employer will use the form to figure the amount of federal income tax to withhold from your pay. Use the IRS Withholding Calculator on IRS.gov to help you fill out the form. This tool is easy to use and it’s available 24/7.
• Estimated Tax.  If you get income that’s not subject to withholding you may need to pay estimated tax. This may include income such as self-employment, interest, dividends or rent. If you expect to owe a thousand dollars or more in tax, and meet other conditions, you may need to pay this tax. You normally pay it four times a year. Use the worksheet in Form 1040-ES, Estimated Tax for Individuals, to figure the tax.
• Life Events.  Make sure you change your Form W-4 or change the amount of estimated tax you pay when certain life events take place. A change in your marital status, the birth of a child or buying a new home can change the amount of taxes you owe. You can usually submit a new Form W–4 anytime.
• Changes in Circumstances.  If you receive advance payment of the premium tax credit in 2014 it is important that you report changes in circumstances, such as changes in your income or family size, to your Health Insurance Marketplace. You should also notify the Marketplace when you move out of the area covered by your current Marketplace plan. Advance payments of the premium tax credit provide financial assistance to help you pay for the insurance you buy through the Health Insurance Marketplace. Reporting changes will help you get the proper type and amount of financial assistance so you can avoid getting too much or too little in advance.

For more see Publication 505, Tax Withholding and Estimated Tax. You can get it on IRS.gov, or call 800-TAX-FORM (800-829-3676) to get it by mail.

If you start a business, one key to success is to know about your federal tax obligations. You may need to know not only about income taxes but also about payroll taxes. Here are five basic tax tips that can help get your business off to a good start.

1. Business Structure.  As you start out, you’ll need to choose the structure of your business. Some common types include sole proprietorship, partnership and corporation. You may also choose to be an S corporation or Limited Liability Company. You’ll report your business activity using the IRS forms which are right for your business type.
2. Business Taxes.  There are four general types of business taxes. They are income tax, self-employment tax, employment tax and excise tax. The type of taxes your business pays usually depends on which type of business you choose to set up. You may need to pay your taxes by making estimated tax payments.
3. Employer Identification Number.  You may need to get an EIN for federal tax purposes. Search “do you need an EIN” on IRS.gov to find out if you need this number. If you do need one, you can apply for it online.
4. Accounting Method.  An accounting method is a set of rules that determine when to report income and expenses. Your business must use a consistent method. The two that are most common are the cash method and the accrual method. Under the cash method, you normally report income in the year that you receive it and deduct expenses in the year that you pay them. Under the accrual method, you generally report income in the year that you earn it and deduct expenses in the year that you incur them. This is true even if you receive the income or pay the expenses in a future year.
5. Employee Health Care.  The Small Business Health Care Tax Credit helps small businesses and tax-exempt organizations pay for health care coverage they offer their employees. A small employer is eligible for the credit if it has fewer than 25 employees who work full-time, or a combination of full-time and part-time. Beginning in 2014, the maximum credit is 50 percent of premiums paid for small business employers and 35 percent of premiums paid for small tax-exempt employers, such as charities.

   For 2015 and after, employers employing at least a certain number of employees (generally 50 full-time employees or a combination of full-time and part-time employees that is equivalent to 50 full-time employees) will be subject to the Employer Shared Responsibility provision.

Get all the tax basics of starting a business on IRS.gov at the Small Business and Self-Employed Tax Center.

Additional IRS Resources:

• IRS Tax Calendar for Businesses and Self-Employed
• Publication 505, Tax Withholding and Estimated Tax
• Publication 334, Tax Guide for Small Business
• Publication 225, Farmers Tax guide
• Publication 535, Business Expenses
• Publication 587, Business Use of Your Home
• Publication 510, Excise Taxes
• Publication 538, Accounting Periods and Methods