WASHINGTON — Want a quick tax refund? File your federal return online and have the refund deposited directly into your bank account.

The Internal Revenue Service launched its online filing system Friday with a promise that people who do their taxes electronically will get refunds in as few as 10 days.

For those who file paper returns, refunds are expected to take four to six weeks, said David Williams, the agency's director of electronic tax administration.

"We really encourage people to file electronically," Williams said, adding that it's fast, free and safe. "We believe e-file is safe and secure and we work with the tax software industry to make sure it stays that way."

One group still will need to file paper forms: those taking advantage of expanded homebuyer tax credits approved by Congress in November. Congress required documentation to claim the credits, so those returns must be done on paper.

Some workers already are starting to receive tax forms from employers and financial institutions. Individual income taxes for 2009 are due April 15.

For those who owe additional taxes, they can file electronically and pay later, as long as payments are received by April 15.

Taxpayers can set a date to have tax payments automatically withdrawn from their bank accounts or pay by credit card.

Last year, two-thirds of individual taxpayers filed their returns electronically. This year, Williams expects about 70 percent to file online.

Taxpayers can file their returns electronically whether they use a paid tax preparer or do it themselves. For families and individuals making less than $57,000, the IRS offers Free File computer software programs that help taxpayers prepare their returns at no charge.

The software walks taxpayers through their returns by asking them a series of questions about their income, expenses and other financial transactions.

Williams said the software is designed for taxpayers to get all the deductions and credits they are entitled to, as long as they accurately answer all the questions.