The Tax Court has ruled that your choice of delivery service to the IRS does indeed matter. In a recent the case (Scaggs, T.C. Memo. 2012-258), the court ruled that using FedEx Express Saver Third Business Day was not an approved method of private delivery service and thus the taxpayer’s petition was not timely filed.
It is important to note that other FedEx services, such as Standard Overnight and 2 Day are approved delivery methods, as well as the services offered by the Postal Service.
For more information, see: http://www.journalofaccountancy.com/News/20126426.htm.