Cotts was born at
Sanquhar in Scotland, the son of William Cotts. He was educated privately and at
Wallace Hall. On 18 March 1901, he married Agnes Sloane who was also from Sanquhar and they had two sons and a daughter. Cotts obtained his early business training in
Dumfries and London and went in 1895 to South Africa, where he developed important business interests, realising the potential of the
Natal coalfields and the transport and other infrastructure that was needed to support the coal and gold mining industries. He also had business interests in Britain and was sometime head of Mitchell, Cotts & Co. of London. The company traded as general merchants, owned collieries and steamships. ==Political and public life==