About 25 percent of taxpayers file their income tax returns within a week of the April deadline – some filing for an extension, according to officials.

The deadline to file returns or file for an extension is Tuesday, April 17. An estimated 9.3 million Floridians are expected to file a tax return for 2011.

“Timely mailed is timely filed,” Mike Dobzinski, spokesman for the Florida office of the Internal Revenue Service, said. “Postmark it by midnight.”

When e-filing, taxpayers must “send” the document by midnight.

About 77 percent of people e-filed in 2010, according to Dobzinski.

With so much paperwork being shuffled, officials and tax preparers are offering tips to help people get their last-minute returns in on time.

Some of the more common mistakes that hold up a return:

n An incorrect or missing Social Security number

n A misspelled or missing name of a dependent

n Filing status errors, such as “married” or “single”

“By making these errors, if we can’t correct it on the spot or it requires contact with the filer, then it could end in a delay of a refund,” he said.

As of March 30, the average refund amount was about $2,860.

“The best way to file is to file electronically,” Dobzinski said, adding that it is more efficient because there is less paperwork involved, hence less steps.

“It’s safe, it’s convenient, it’s fast,” he said.

Dobzinski warned e-filers to be careful though when typing in information, like W-2 earnings and deductions. Double check everything before sending.

“It (e-filing) can get you your refund a lot quicker,” he added.

Jackson Hewitt Tax Services agreed. According to a recent prepared statement, e-filing is faster, more accurate and includes a confirmation receipt, so taxpayers know a return was received before the deadline.

The company offered the following advice when filing last minute:

n Have all necessary tax documents: This includes wage statements (Form W-2), Form 1099, unemployment compensation received (Form W-2G), Social Security cards, driver’s licenses, last year’s federal tax returns, mortgage interest paid and real estate taxes (Form 1098), total cash and non-cash charitable contributions, deductions records, and Form HUD-1 or equivalent.

n Do not overlook money-saving credit and deductions: From benefits relating to life changes in 2011, to new and extended tax laws, credits and deductions can help to maximize a tax refund or reduce the taxes owed.

Dobzinski echoed that.

“Credits are good because they reduce your taxes dollar for dollar, rather than a percentage,” he said.

Dobzinski pointed out the earned income tax credit. Once for low-income workers, those who lost income in 2011 due to unemployment or because they simply were making less money, could now be eligible for the credit.

He also noted the home energy credit for non-business properties. This credit has been extended one year through 2011, so any energy-efficient projects done, like insulation or new air conditioning, could be applicable.

“You may be eligible for a credit there, so don’t forget that,” he said.

n Be prepared to pay now if you owe: If you think you are going to owe on your taxes and are unable to pay the full amount due, it is important to pay as much as possible to reduce interest charges or any potential penalties.

n Ask about an extension: Requesting an extension gives you until Oct. 15 to file a return. To file an extension, create a draft of your income return, which provides an estimate of your total refund or balance due. If the estimate shows you owe, all taxes must still be paid by the April 17 deadline.

In Florida, 469,000 are expected to file for an extension for 2011.

“If you can’t make the deadline, file for an extension,” Dobzinski said.

It keeps the taxpayer from paying a late filing penalty of 5 percent.

“If you owe money, there will be interest on the late payment,” he said.

The document – Form 4868 – can be mailed or e-filed.

Dobzinski also pointed out the Fresh Start Penalty Relief Initiative.

It is six-month extension on paying taxes for those who were unemployed for at least 30 consecutive days last year up through April 15 or were self-employed and their 2011 business income decreased 25 percent or more due to the economy, he said.

More information can be found by visiting: www.irs.gov.

For taxpayers who decide to skip e-filing for regular mail, local postal officials want to remind them that there are no extended hours Tuesday.

“We did it last year and just did not see the traffic to warrant the extension,” Debra Mitchell, spokeswoman for the U.S. Postal Service, said.

The Cape’s main branch, near City Hall, will be open until 6:30 p.m.

After hours, people can drop off their returns in the blue outside collection boxes at the Fort Myers Processing & Distribution Center, at 14080 Jetport Loop Road, Fort Myers. The final pick up Tuesday is scheduled for midnight.

“Normally, the last collection out at the blue boxes is 8 p.m.,” she said.

Self-service shipping and mailing is available in the lobby of the Cape’s main branch. There is certified mail, and Mitchell suggested that people check the weight of their envelopes and make sure there is enough postage on them.