Believe it or not, taxpayers are just days away from their final income tax deadline to file for the 2015 tax year. Those who received an extension of time to file must do so by midnight on Monday, Oct. 17 or face possible interest and penalties on any tax due.

Here are some things to keep in mind for taxpayers who haven’t yet filed:

Use Direct Deposit. If a taxpayer is due a refund, the fastest way to get it is to team e-filing the return with direct deposit for the refund. Direct Deposit is proven performer; it’s the preferred transmission method of eight out of 10 taxpayers who get a refund.

Use IRS Online Payment Options. If taxpayers owe tax due, the best way to pay them is with IRS Direct Pay. It’s simple, quick and free. Check out other options by visiting IRS.gov and clicking the “Payments” tab.

Don’t Overlook Tax Benefits. Even though time is ticking down, taxpayers should remember to claim those credits and deductions they’re due. That includes the Earned Income Tax Credit and the Saver’s Credit. The American Opportunity Tax Credit or the Lifetime Learning Tax Credit are good to help offset college costs.

Keep a Copy of the Return. Taxpayers should retain a copy of the return as filed, along with their supporting documents, for at least three years. Doing so will help by keeping information handy that will be needed next tax season.

File on Time. If tax due is owed, taxpayers must file on time to avoid a potential late filing penalty. Those who cannot pay all the taxes owed should pay as much as possible now, in order to reduce interest and penalties for late payment. It may also be possible to qualify for an installment agreement that allows payment over time.

Breaks for the Military. Members of the American military and those serving in combat zones generally get more time to file. Qualifying taxpayers typically have until at least 180 days after leaving the combat zone to file returns and pay any tax due.

Help for Disaster Victims. The IRS typically grants extensions to taxpayers within federally declared disaster areas. For example, taxpayers in parts of Louisiana and West Virginia currently have additional extensions beyond Oct. 17.