What goes wrong
Bundles have a quantity. Read it before you order one bundle and expect a hundred.
Packaging Boxes lists Single wall boxes for this line. Use the pack count from the last clear week of that size.
The check before you reorder
The single wall range is the general cube. It is not the double wall range, and it is not a postal format by itself.
Store sizes in columns. The print on the bundle is the size. The end of the bundle is not.
Dispatch on that order
TradePro at Packaging Boxes, for trade businesses, starts at 5% off and goes up to 10% when you spend over £1,000 a month, and it adds BACS. It does not change which Single wall boxes you needed.