A system includes one or more memory devices storing instructions, and one or more processors configured to execute the instructions to perform steps of a method for providing customer data access during a migration process. The system may initiate a transfer of customer data from a source data server to a system platform and transfer a subset of the customer data to a temporary data storage. The system may modify the temporary copy of customer data and generate an instruction to modify the permanent copy of customer data. In response to the completion of the transfer of customer data from the source data server to the system mainframe, the system may then transfer and execute the instruction to modify the permanent copy of customer data.