does sun country charge for carry on ?Fees apply to each piece of checked baggage on Sun Country Airlines. According to their baggage limits, checked baggage is limited to 50 pounds and 62 linear inches in weight. Your first and second checked bags will cost you separately if you select the bag option when booking your reservation or checking in online; if you decide to check a bag at the airport, there will be a fee. Whether you pay in advance or at the airport, a third checked bag will cost.

Heavier luggage will be charged more than just the checked bag cost.
You can't check a suitcase that weighs more than 70 pounds on flights to and from Jamaica and Puerto Rico. 

When you fly with Sun Country, you are entitled to one complimentary under-seat item. If you need to bring more luggage, prices vary depending on when you make your payment. You are allowed to bring a carry-on together with your first checked bag for or less if you select the option when making your reservation. Your second and third checked luggage will be charged at the time of booking.

If you choose your bag option before finishing your online check-in, you will be charged for a carry-on or first checked bag. The cost of waiting till you get to the airport.