The IRS has some advice for taxpayers who missed the tax filing deadline.

Don’t panic but file as soon as possible. If you owe money the quicker you file your return, the less penalties and interest you will have to pay. Even if you have to mail us your return, the sooner we receive it, the better.

E-file is still your best option.  IRS e-file programs are available for most taxpayers through the extension deadline – October 15, 2012.

Free File is still available.  Check out IRS Free File at irs.gov/freefile.  Taxpayers whose income is $57,000 or less will qualify to file their return for free through IRS Free File. For people who make more than $57,000 and who are comfortable preparing their own tax return, the IRS offers Free File Fillable Forms. There is no software assistance with Free File Fillable Forms, but it does the basic math calculations for you.

Pay as much as you are able. Taxpayers who owe tax should pay as much as they can when they file their tax return, even if it isn’t the total amount due, and then apply for an installment agreement to pay the remaining balance.

Installment Agreements are available.  Request a payment agreement with the IRS.  File Form 9465, Installment Agreement Request or apply online using the IRS Online Payment Agreement Application available at irs.gov.

Penalties and interest may be due.  Taxpayers who missed the filing deadline may be charged a penalty for filing after the due date. Filing as soon as possible will keep this penalty to a minimum.  And, taxpayers who did not pay their entire tax bill by the due date may be charged a late payment penalty. The best way to keep this penalty to a minimum is to pay as much as possible, as soon as possible.

Although it cannot waive interest charges, the IRS will consider reductions in these penalties if you can establish a reasonable cause for the late filing and payment. Information about penalties and interest can be found at Avoiding Penalties and the Tax Gap.

Refunds may be waiting. Taxpayers should file as soon as possible to get their refunds. Even if your income is below the normal filing requirement, you may be entitled to a refund of taxes that were withheld from your wages, quarterly estimated payments or other special credits. You will not be charged any penalties or interest for filing after the due date, but if your return is not filed within three years you could forfeit your right to the refund.

More information can be found at irs.gov.