Indian Contract Act, Ch II Agreement in restraint of trade, void

Every agreement by which anyone is restrained from exercising a lawful profession, trade or business of any kind, is to that extent void.

Exception 1 : Saving of agreement not to carry on business of which goodwill is sold-One who sells the goodwill of a business may agree with the buyer to refrain from carrying on a similar business, within specified local limits, so long as the buyer, or any person deriving title to the goodwill from him, carries on a like business therein, provided that such limits appear to the court reasonable, regard being had to the nature of the business.