There are many different numbering schemes for assigning numbers to entities. These generally require an agreed set of rules, or a central coordinator.

Numbering schemes include:

• The E.164 numbering plan for telephone numbers, including:
  • The North American Numbering Plan
  • The UK National Numbering Scheme
  • Country calling codes
• The IP address allocation scheme (IANA)
• The DNIC prefixes of X.25 NUAs assigned by the ITU http://www.itu.int
• The NSAP allocation scheme
• The MAC address allocation scheme for hardware addresses of certain networking products
• The UPC numbering scheme for barcodes on products
• The European Article Numbering-Uniform Code Council (EAN-UCC) numbering scheme, including
  • ISBN codes for books
  • ISSN codes for periodicals
• Dewey Decimal Classification and Universal Decimal Classification for books
• Social Security numbers
  • Social Security number#United States
  • Canadian Social Insurance Numbers
  • French INSEE numbers
• Production code number
• Vehicle identification number
• Stamp numbering system
• Credit card number prefixes
• FIPS place codes
• Postal codes
  • ZIP codes
• CAS registry numbers for chemical compounds
• EC numbers for identifying enzymes
• UN numbers for (classes of) hazardous substances
• E numbers for food additives
• ICD for diseases
• West American Digest System legal topic numbering scheme
• Road numbering schemes
  • British road numbering scheme
  • European route by UNECE
  • Interstate highway
  • Edmonton, Alberta#Street system
  • Montreal, Quebec#Street system
  • List of Australian highways#Route numbering systems
• Use of ordinals by monarchs
  • Princes of Reuss
  • Popes
• House numbering schemes

See also: country code, naming schemes.