We have a deck that is quite high. It also has a bench seat. Someone told me the seat is not allowed by code, can you explain?

The use of a bench seat usually allows children to climb under or over the seat and fall off the deck. Bench seats need to have a 36” high seat back that prevents someone from falling over the back. If this seat is over 60” from the ground the seat back needs to be 42” high. Remember that decks are dangerous places and building them properly is critical to your families safety. I recommend you obtain a permit for all the requirements of your area as many jurisdictions have specific rules they enforce.