A representative of the High Commission of India in Ottawa states that the surname "Singh" does not necessarily identify a person as Sikh; however, in 95 percent of cases, Singh is a surname used by Sikhs (6 July 1992). The representative adds that Singh may be used by Indians other than Sikhs, possibly with different spellings.
According to a representative of the National Alliance of Canadian Sikhs in Toronto, Singh is a middle name which is commonly used by Sikhs although other Indians may also use it (7 June 1992). The representative maintains that surnames are of no significance in India since people are called by their first and middle names; they are identified by their fathers' names. Unless applicants for passports specifically request in their application forms that their surnames be mentioned in their passports, the government of India will issue passports in their first and middle names (Ibid.). Hence, Sikhs living abroad whose surnames are not mentioned in their passports may use Singh as a surname. A representative of the World Sikh Organization in Ottawa holds that while Singh is part of every Sikh's name, not every person whose surname is Singh is Sikh (6 July 1992). The representative adds that Singh can be a middle name or surname.
Additional and/or corroborating information on the above subject is currently unavailable to the IRBDC.
References

High Commission of India, Ottawa. 6 July 1992. Telephone Interview with Representative.

The National Alliance of Canadian Sikhs, Toronto. 6 July 1992. Telephone Interview with Representative.

The World Sikh Organization, Ottawa. 6 July 1992. Telephone Interview with Representative.