The Internal Revenue Service says a postmark is fine when it comes to proving your return met the filing deadline. But some taxpayers want a little more assurance.

When your tax return absolutely, positively has to get to the IRS, you might want to use a private delivery service.

The IRS has authorized the following companies to handle delivery of tax returns:

  • DHL Express — The IRS recognizes DHL’s Same Day and Next Day (10:30 a.m., 12 p.m. or 3 p.m.) services, as well as the company’s 2nd Day service.
  • FedEx — FedEx options accepted by the tax office include Priority Overnight, Standard Overnight and 2nd Day delivery. International taxpayers can use FedEx’s International Priority and International First services.
  • United Parcel Service — The guys and gals in the brown trucks can take your returns to the IRS via Next Day Air, Next Day Air Saver, 2nd Day Air, 2nd Day Air A.M., Worldwide Express and Worldwide Express Plus.

The delivery options listed above for each company are the only ones that the IRS will accept under its “timely mailing as timely payment” rule. Other delivery options offered by the companies are not IRS-authorized.

According to the IRS, the “postmark” date of an authorized private delivery service is generally the date the company records in its database or marks on the mailing label. Check with each firm on how to get written proof of your mailing date for tax purposes.

And remember that private delivery services do not ship to post-office boxes. You must use the U.S. Postal Service’s Express Mail for any item addressed to an IRS box address.

Get the envelope address right

What if you’re relying on the tax return envelope, which in most cases has neither a P.O. box nor a street address? Call the delivery service of your choice for guidance. The companies might have the data in their files or be equipped during tax season to accept the more limited address.

But make sure before you let the delivery representative drive away with your tax return.

You also can call the main IRS customer service line, (800) 829-1040, for the specific delivery address for your return. But as the tax deadline nears, be prepared to wait or be put on hold.

You might have better luck calling your local IRS office for the street address of your appropriate IRS service center.

Procrastinating e-filers

Paper return filers aren’t the only ones who are delaying their inevitable tax duties. In fact, the ease of filing electronically might tempt you to wait longer than you normally would to complete and send in your taxes.

Don’t.

True, you do have a bit more control when you can simply push the “Enter” button on your keyboard and have the information whisked through cyberspace to the IRS. The agency considers your e-filed return on time if the authorized electronic return transmitter (tax-speak for an approved IRS e-file program participant, either a person doing the filing for you or the software company you use to do it yourself) postmarks the transmission by the due date.

The electronic postmark is when the authorized electronic return transmitter received the transmission of your e-filed return on its host system. The date and time in your time zone determines whether your e-filing is on time.

But make sure you give yourself enough time to meet the deadline. If you haven’t even started doing your return using tax software, you might be surprised — and dismayed — to learn that, while it is usually quicker than filling out forms by hand, it still takes time. Rushing to finish by the deadline could cause you to make some costly errors.

And don’t forget that computers crash and Internet connections are lost at the most inopportune times. So don’t wait until 11:59 p.m. April 15 to electronically send your return.

Log on earlier in the day and be done with your taxes with filing time to spare.

If you are old-fashioned in the way you handle your tax return, and prefer a mad dash to the post office, see ” Many happy, but last-minute, returns.”