You only have a right to a retroactive pay raise if you have a written employment agreement which guaranteed you that raise as of a certain date. If you had such a contract and the company did not give you the raise, you could sue for "breach of contract" for the additional money, such as in small claims court.  But without a written contract specifying the raise, all raises (and pay generally) is at the discretion or free choice of the employer: the employer can decide whether to grant you the raise or not, and if so, when. Without a written contract, you do not have a right to the raise as of any given or specific date: you get it if and when the employer wants to give one to you. So without a contract, you have no entitlement to the raise.