Whether or not you can recycle a pizza box has more to do with where it came from. It has to do with grease.
Frozen pizzas bought in stores are wrapped in plastic, which keeps the grease away from the box. These are recyclable.
If it is delivered or picked up at a pizzeria, put the box in the trash. Grease interfers with the recycling process.
The short answer: Throw away take-out pizza boxes; recycle the frozen pizza boxes.