A non-solicitation agreement restricts an individual (usually a former employee) from soliciting either (a) employees or (b) customers of a business after leaving the business. Non-solicitation language can come in the form of an entire document or a clause within another document, like an employment agreement or independent contractor agreement. Many companies require managers and professionals to sign non-solicitation agreements to prevent them from soliciting (a) current employees, or (b) current customers. The most common issue in non-solicitation agreements is that if they are not "reasonable" (as defined on a case-by-case basis), they can be considered to be restraint of trade. That is, the agreement unreasonably restricts someone from doing business. A lawsuit is filed and a court decides, or in some cases a state has laws limiting restrictive covenants like non-solicitation agreements. In your case since the client n more work with your current employer, this agreement may not hamper the proposed employment with the ex client of your current company. Well, you can challenge the legal problems if any arises on this ground also.