The Internal Revenue Service is scheduled to begin accepting individual income tax returns starting Wednesday.

The IRS had delayed tax season for about eight days because of the late passage of the fiscal cliff deal tax legislation by Congress and the Obama administration on New Year’s Day (see IRS Delays Tax Season until End of January).

The IRS confirmed that the tax season opened successfully. "The Modernized e-File (MeF) System successfully opened this morning at 9:00 am, Eastern Standard Time (January 30, 2013) and is now operational for Individual Tax Returns and Extensions," it said in an email to tax professionals on Wednesday morning.

The IRS announced earlier this month that it would begin processing most individual income tax returns on Jan. 30 after updating its forms and completing the programming and testing of its processing systems.

The IRS contended that it had anticipated many of the tax law changes made by Congress under the American Taxpayer Relief Act, but the final law requires some changes before the IRS can begin accepting tax returns.

The IRS began accepting some business tax returns earlier this month (see IRS Begins Accepting Business Tax Returns).

Using e-file is the best way to file an accurate tax return, the IRS insisted, and using e-file with direct deposit is the fastest way to get a refund.

For the first time this tax season, the IRS's "Where's My Refund?" online tool will provide personalized refund timelines for taxpayers.

Many major software providers have been accepting tax returns in advance of the Jan. 30 processing date, the IRS noted. These software providers are able to hold onto the returns and then electronically submit them after the IRS systems open as the IRS has lifted its prohibition against stockpiling of tax returns this tax season. The IRS advised taxpayers who use commercial software to check with their provider for specific instructions about when they will accept your return. Software companies and tax professionals then send the returns to the IRS, but the timing of the refunds is determined by IRS processing, which starts Jan. 30.

However, the IRS has warned that it will not be able to accept some types of individual tax returns, including those with education tax credits, until at least mid-February (see Education Credit Returns on Hold until Mid-February).

Some tax returns containing other forms will not be processed until late February or March. They include:

• Form 3800 General Business Credit
• Form 4136 Credit for Federal Tax Paid on Fuels
• Form 4562 Depreciation and Amortization (Including Information on Listed Property)
• Form 5074 Allocation of Individual Income Tax to Guam or the Commonwealth of the Northern Mariana Islands
• Form 5471 Information Return of U.S. Persons With Respect to Certain Foreign Corporations
• Form 5695 Residential Energy Credits
• Form 5735 American Samoa Economic Development Credit
• Form 5884 Work Opportunity Credit
• Form 6478 Credit for Alcohol Used as Fuel
• Form 6765 Credit for Increasing Research Activities
• Form 8396 Mortgage Interest Credit
• Form 8582 Passive Activity Loss Limitations
• Form 8820 Orphan Drug Credit
• Form 8834 Qualified Plug-in Electric and Electric Vehicle Credit
• Form 8839 Qualified Adoption Expenses
• Form 8844 Empowerment Zone and Renewal Community Employment Credit
• Form 8845 Indian Employment Credit
• Form 8859 District of Columbia First-Time Homebuyer Credit
• Form 8864 Biodiesel and Renewable Diesel Fuels Credit
• Form 8874 New Markets Credits
• Form 8900 Qualified Railroad Track Maintenance Credit
• Form 8903 Domestic Production Activities Deduction
• Form 8908 Energy Efficient Home Credit
• Form 8909 Energy Efficient Appliance Credit
• Form 8910 Alternative Motor Vehicle Credit
• Form 8911 Alternative Fuel Vehicle Refueling Property Credit
• Form 8912 Credit to Holders of Tax Credit Bonds
• Form 8923 Mine Rescue Team Training Credit
• Form 8932 Credit for Employer Differential Wage Payments
• Form 8936 Qualified Plug-in Electric Drive Motor Vehicle Credit

For a complete list of delayed forms, click here.