This is a tip for those of you who are overseas and will be filing a paper income tax return for 2015 with the IRS.
If you are shipping paper tax returns to the IRS, please do not use DHL. Use FedEx or UPS.
Or, of course, you can use R.O.M. (regular old mail).
In years past, DHL was one of the approved private delivery services for sending tax returns to the IRS. As of May, 2015, only UPS and FedEx are “approved” by the IRS for delivery. See Notice 2015–38 for more information, and to see exactly what type of service you must buy from FedEx and UPS in order to make the IRS happy.
The last thing you want to do is be rushing to file your tax return on time, only to screw it up by using a non-approved delivery method.
Finally, thanks to Luku for the reminder about this.