Count the job, not the habit
The quantity is the large-letter orders only.
Count large-letter orders.
Where it lives during that week
Store them with the postal sizes, not with the general cubes.
Order this range for that format and book wraps if the goods are a book rather than a letter-shaped box.
The reorder line
Say large letter and the size on the reorder.
A Friday order on Packaging Boxes that includes Large letter boxes aims for Monday. A bank holiday on Friday or Monday moves that delivery. The 3pm cutoff is still the same-day dispatch rule.
Open Large letter boxes when you already know this line. Read the pack count. Packaging Boxes will still dispatch an order placed by 3pm on the same day.