You will require electricity and/or natural gas interval data along with details of which meters feed which buildings. Interval data is best supplied in NEM12 and CSV formats. NEM12 is automatically processed with minimal user input, whereas CSV data must conform to a templated format.
For building and meter metadata, knowledge of which building has what NMI or MIRN and the relationship between utility meters if there are child meters is vital.
Having copies of invoices allows you to enter tariffs if not present, and then to use the bill to validate the calculations completed by Deep Energy.