If you filed for a federal tax extension last April, you’ll still need to send in your return by Oct. 15, despite the government shutdown.

And millions of you had better get busy. According to the IRS, as of the last week of September, many of the 12 million taxpayers who sought extensions had yet to file. (Of course, you needed to pay at least 90 percent of your estimated tax back in April to avoid any penalties.)

If you have questions about federal forms, or need help with last-minute calculations, don’t look to a live IRS tax expert for advice during the shutdown. Customer service agents have been furloughed, and walk-in taxpayer assistance centers are closed. However, you may be able to find answers to your questions on the IRS automated phone system at 800-829-1040 or on its website. You can also give us a call here at NFS toll free at 800-560-4637.

The IRS says it prefers that you file your return electronically since those returns are processed automatically. If you choose to file a paper return, it won’t be processed until the government is back up and running. Still, your return must be postmarked by Oct. 15 to be considered on time, the IRS says on its site. If you miss the deadline, you’ll face fines.

If you owe money and can only pay a partial amount, you must still meet the Oct. 15 deadline to avoid the late-filing penalty — 5 percent per month —  that would otherwise apply to any unpaid balance after Oct. 15, the IRS said on its site. However, 3 percent annual interest, compounded daily, and late-payment penalties, will continue to accrue.

Taxpayers who sought extensions and were affected by the severe storms and flooding that hit parts of Colorado have more time, until Dec. 2, to file and pay. Military members serving in a combat zone have at least 180 days after they leave that zone to file returns or pay any taxes due.