Consultants however do not need to base their advice on law. Legal regulations will be a subset of their entire advice, in fact consultants at times may also hire lawyers to vet a potential deal which is being made. The basis for their advice could be their own experience, best practices in industry, lot of data analysis and at times basic common sense backed by justification / facts.

 The Consultants however do not need to base their advice on law. Legal regulations will be a subset of their entire advice, in fact consultants at times may also hire lawyers to vet a potential deal which is being made. The basis for their advice could be their own experience, best practices in industry, lot of data analysis and at times basic common sense backed by justification / facts.

Moreover, at least in India, legal firms typically hire lawyers as retainers whereas consultants are typically hired as employees. This results in differential income tax treatment and reduced employer obligations (in case of retainers).

https://www.quora.com/What-is-the-difference-between-a-lawyer-and-a-consultant