Clean card goes in your paper & card boxes; greasy, food-soiled card goes in the brown bin.
paper & card recycling boxes
Grease and cheese contaminate the paper-recycling process, so St Albans specifically excludes food-soiled pizza boxes from the paper & card boxes. Tear the box: recycle the clean parts, bin the greasy base.
Getting it right
Lid and edges are usually clean — flatten and put them in your paper & card boxes.
The greasy base (and any stuck-on cheese or leftovers) goes in the brown general waste bin.
Leftover food scraps go in your weekly food caddy, not the box.