Stacking limit by number (n in a box)

Identical packages may be stacked only up to the number written in place of n.

Who puts it on the box

The sender, from the strength of the packages.

How to read it

ISO 780:1997 put it as “n indicates the maximum number of packages stacked”. Because shippers do not all read that the same way (the whole stack, or the packages on top of the bottom one), stay below the figure when in doubt and ask the sender. The 2015 edition lets the figure be corrected by hand.

What it does not promise

It does not promise the stack is stable at that height on any floor or pallet, and it does not apply to different, heavier packages put on top.

A mark on a parcel is the sender’s statement about what is inside and how it should be handled. It is not a certificate that the parcel is packed safely, that anyone handled it as marked, or that your carrier accepts it: for what you may send, read the carrier’s own terms.

What it looks like: Boxes drawn in a stack with a number n written in one, and a crossed-out box on top: the number replaces n, for example 3.
Standard: ISO 780:2015, symbol No. 16 — Stacking limit by number
Kind of mark: A handling symbol from ISO 780, the international standard for handling marks on distribution packages. ISO 780 marks are always black; they say how to handle the package, never that its contents are dangerous.
Also called: Max stack; Stack n high; Stacking limit

Other marks with the same shape

Centre of gravity (target cross)The centre of the mark shows where the centre of gravity of the…Do not roll (crossed rolling arrows)Do not roll or tumble the package end over end to move it.Stacking limit by mass (XX kg on a box)No more than the mass written may be stacked on top of this package.Do not stack (crossed box on top)Nothing may be stacked on top of this package.

Sources

Each document was fetched and read on the date shown. Written in our own words; quotations are the documents’ wording.

Symbol list — IBJ / bravecroc (graphical-symbol file vendor): ISO 780 EN Symbols (2015-12): the 17 ISO 780:2015 symbols with their numbers and titles — Lists ISO 780 symbol No. 16, “STACKING LIMIT BY NUMBER”, with a reference drawing, in the 2015 numbering. Checked 2026-09-27.
Standard (preview pages) — ISO (preview pages published by iTeh Standards): ISO 780:1997 Packaging — Pictorial marking for handling of goods, 4th edition (preview: clause 2 and part of Table 1) — Clause 2.4.4: in the symbol “stacking limitations by number”, n indicates the maximum number of packages stacked. Checked 2026-09-27.
Standard (preview pages) — ISO (preview pages published by iTeh Standards): ISO 780:2015 Packaging — Distribution packaging — Graphical symbols for handling and storage of packages, 5th edition 2015-12-01 (preview: foreword to Table 1) — Clause 4.1: for symbols No. 15 and 16 the number may be corrected by hand; the introduction says the symbols give no guarantee of satisfactory handling. Checked 2026-09-27.