Some Child Tax Benefits applicants who do not have appropriate immigration document do not qualify to obtain a Social Insurance Number. Under this circumstances, client must not call Social Insurance Registry for help. Client who has received a letter from Canada Revenue Agency or from other private organizations, seeking for client’s proof of SIN, or a proof from Service Canada that explains why they can not obtain a SIN, must visit their nearest Service Canada Centre for assistance. CRA often requires client to obtain a Service Canada SIN application rejection form in order to provide the client with their Individual Tax Number (ITN).