Why follow Standardised Taxonomy across domains

Enables buyers and employee requisitioners to find all suppliers of a
given category
Enables purchasing managers to analyze expenditures and perform
strategic sourcing
Consistent coding across company divisions, suppliers, and information
systems gives uniform picture of company expenditures.
Integrates procurement card statement categories with all purchase
transactional data.
One numbering system integrates entire processing flow - from RFPs, to
ordering, to accounts payable, to general ledger.
Facilitates control over and compliance to spending limits and
authorized commodities by individuals and departments.
A standardized, already devised code is easy to implement and saves the
company time and expense in developing its own.