Why standard units matter

International trade documents move between suppliers, forwarders, carriers, and customs in many countries. Using a standard unit and its code avoids confusion between, for example, a metric tonne and a short ton, or a piece and a set. The codes below come from UN/CEFACT Recommendation 20, the standard list of units of measure used in international trade.

Mass and weight

UnitSymbolUN/CEFACT code
KilogramkgKGM
GramgGRM
Metric ton (tonne)tTNE
PoundlbLBR
OunceozONZ

Length

UnitSymbolUN/CEFACT code
MetremMTR
CentimetrecmCMT
MillimetremmMMT
KilometrekmKMT
FootftFOT
InchinINH

Area and volume

UnitSymbolUN/CEFACT code
Square metreMTK
Cubic metreMTQ
LitreLLTR
MillilitremLMLT

Quantity and count

UnitSymbolUN/CEFACT code
PiecepcH87
Unit (one)C62
Number of pairsNPR
DozenDZN
SetSET

Shipping containers

UnitSymbolUN/CEFACT code
Twenty-foot container (TEU)20
Forty-foot container (FEU)21

Important note

Codes follow UN/CEFACT Recommendation 20 (Codes for Units of Measure Used in International Trade). For the complete and authoritative list, see the UNECE Code List Recommendations. Customs declarations may require a specific statutory unit, so always confirm the required unit with the customs authority or your broker.