Law was made Football in the Community officer with Chesterfield before taking over as manager from John Duncan in the spring of 2000. The change was too late to save the Spireites from relegation in 1999–2000, but with some shrewd signings by Law, the team dominated Division Three in 2000–01 and led the table, until the pressures of the Football League enquiry into financial irregularities started to impact on performances. Despite a nine-point deduction, Law nevertheless led Chesterfield to third place and automatic promotion to Division Two.
On 1 January 2002 he joined division 1 side Bradford City replacing Jim Jeffries as manager. Law was sacked in November 2003 during which the club was in administration and second from bottom of division 1.
On 14 May 2007 he was appointed as manager of Alfreton Town. In March 2008 he was set to return to Bradford as manager of Bradford Park Avenue, until Park Avenue were forced to call off the deal and apologise to Alfreton Town.
On 25 May 2011 Law signed a new contract along with assistant Russ O'Neill keeping them with the club till June 2014.