The General Rule: When You Mail Is When You File
As most last-minute filers already know, the general rule for the IRS is that as long as you meet the appropriate requirements, the date that you mail your return and tax payment to the IRS is treated as the date that you filed or paid your taxes. This rule applies to returns and other required documents for which a specified date or period is given in the tax laws.
For example, for filing a tax return, the April 15 deadline qualifies for the mailing-date rule. But if you were already late and were trying to get taxes filed in order to avoid further extra payments for failing to file, then the mailing-date rule won't stop the clock from running on interest and penalties.
So if you put your return in a mailbox on April 15, but it doesn't get postmarked until April 16, you're treated as having filed late. To avoid this problem, you can use registered or certified mail to establish that it has officially been mailed. Your postmarked receipt establishes when you filed, even if your return subsequently gets lost.
If you don't want to use the U.S. Postal Service, you have a few other alternatives. Certain private-delivery services, including DHL Express, FedEx (FDX), and United Parcel Service (UPS), qualify for the mailing-date rule. But in general, you have to use next-day or second-day delivery services; standard ground rates won't qualify for the rule. The IRS maintains a list of qualifying delivery services.
The Benefits of Electronic Filing
Electronic filings are treated as having been filed on the date of the electronic postmark: The record of the date and time that your return gets transmitted.
You won't necessarily get proof of e-filing right away. According to the IRS, the tax professional who files your return electronically will get confirmation within 48 hours that your return was accepted, or if it needs corrections and retransmission. That confirmation should bear the original date and time that you filed it.
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