What is the Mail Box Rule?

Lainie Petersen

In the United States (U.S.), the mail box rule, also known as the postal rule or presumption of receipt rule, is a legal doctrine that states the acceptance of a contract is effective upon its posting to the U.S. mail. This rule is an exception to most contract law in countries that follow common law, which states contracts are effective upon communication. Contracts can include such items as tax payments, insurance premiums and utility payments. Under this legal principle, once the sender has mailed a letter, he can presume the sender has received it; the recipient regards the contract as on-time based on the postmark date.

In the United States, the mail box rule is a legal concept stating the acceptance of a contract is effective upon sending it through the postal service.
In the United States, the mail box rule is a legal concept stating the acceptance of a contract is effective upon sending it through the postal service.

When it comes to forms of payment, a payment is said to have been made on the date the payer properly mailed his check in a mailbox or handed it to a postal employee. As such, many companies that receive payment will refer to the postmark date, not the date it actually received the payment, when determining whether a payment was made on time.

Most companies recognize the postmark date of payments as the date they received the actual payment.
Most companies recognize the postmark date of payments as the date they received the actual payment.

There have historically been challenges to this law. Some argue that common sense should prevail when mailing a contract or a payment. If a sender knows, for example, there was a fire in their apartment building's mail room the day they left their letter to be sent out, he or she really can't presume the letter was sent to its recipient.

Delivery service also can be an issue. U.S. Courts have issued conflicting rulings as to whether a postmark or confirmation of receipt from a delivery service other than the U.S. Postal Service meets the criteria of the mail box rule. In the United States, at least, it is probably wise to only use the U.S. Postal Service if the sender suspects the mail box rule might need to be invoked.

Getting proof of mailing may also be a good idea. While a postmark from the official postal service usually is sufficient for proving date of mailing, there are times when a letter might get lost in the post office and not actually be postmarked for a few days. Also, a postmark from an office postage meter may not itself be sufficient under the mail box rule. Senders may best protect themselves by bringing their letter to the post office and asking for proof of mailing; for even greater protection, consumer can request a tracking service and proof of receipt.

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Discussion Comments


I have a small business in Silver Spring, MD. I have been mailing checks to my landlord's real estate agent between the first and the fifth of every month. And they require me to have the payment by the 10th. I just renewed my lease and they mailed me a year of late fees of $160 a month. I wonder if the mailbox rule can be applied in this case. Please advise. Thank you!


@bagley79 - There is something similar to that when it comes time to mail in federal and state taxes. The state taxes don't seem to be as much of an issue, but I know we always have several warnings about getting our federal taxes filed on time.

They must be postmarked by April 15th in order to be on time. They also have until midnight of that date to get it done. I remember seeing pictures on the news of cars being lined up at the main post office to make sure they meet the deadline.

If they wait until evening to do this I don't know how they would be able to get any kind of receipt. From everything I have seen they are just dropping them in the outside mailbox, but since they are at the main post office, they will be considered on time.


If we are making any charitable contributions at the end of the year and want them to be applied as a tax deduction for the current year, we always have to make sure they are postmarked on or before December 31st.

I don't like to wait until the last minute, but there have been times that I have waited until the very last day of the year to get them postmarked.

When I do this, I always go to the post office and get some kind of proof or receipt showing the letter as being postmarked that day.

I have never had to use this for anything, but is always good to have just in case it's needed as proof.


@indemnifyme - Well, that rule is certainly great for customers. I almost feel bad for the companies though-I'm sure you're not the only one that mails their bills at the last minute every month!

Actually, I take that back. I bet the companies probably have this factored into their business plans or something. They probably make bills due 5 days before they actually plan on receiving the money!


The mail box rule is pretty awesome as far as bill paying goes. I'm on a pretty tight budget, so sometimes I have to wait until the day the bill is due to mail my check.

Honestly, sometimes I gamble with the system a little. I'll mail my check the day it is due, but I may not have money in my account that day. I know this is a little risky but I figure as long as the money gets there by the time the company receives the check I'll be okay!


I knew this applied to tax payments, because I have always heard that your tax returns are considered to be on time as long as they are postmarked by April 15. This is convenient for people who actually owe the government and need extra time to save up for their payments.

However, lots of people are due refunds. This is definite motivation to do your taxes early. I almost always get at least $1,000 back, so I usually send in my tax return sometime in February to get the ball rolling.

My friend who owns her own business loves the mailbox rule, though. She usually has to pay in about $3,000, and sometimes, she needs all the extra time she can get to scrape up the money.


I had no idea that this rule existed! This is wonderful news. I always try to send my payments in plenty of time for the recipient to get them before the due date, but I have had situations where that wasn’t possible.

Once, the utility company was late sending out their bills, and I didn’t receive mine until two days before the due date. There was no way the payment would get to them on time, so I drove thirty miles to pay the bill in person. Had I known about the mailbox rule, I would have just gone to the post office down the street.

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