(INDIANAPOLIS) – The U.S. Postal Service says next Monday, December 14th, is their busiest mailing and *shipping* day for holiday packages, letters and cards. Monday, the 21st, will be their busiest *delivery* day … and they’ll deliver a total of 15.5 billion pieces this season.

Indianapolis USPS Spokesperson Mary Dando says there are plenty of things you should do to make sure your packages arrive in a safe and timely manner – such as making sure you have correct zip codes, and clearly printed addresses in capital letters for easy reading.

Forwarding addresses and information should be included inside packages in the event that they open. Also, the postal service says to make sure batteries are shipped in separate boxes or compartments from your main items. Dando says research has shown that friction between batteries and other items can cause them to explode.