You can import reporting unit data from an Excel workbook. You can import reporting unit codes, names and notes, but the presence of at least a single reporting unit code in column 1, line 1 is all that is required for a successful import.
You can also use a template to import reporting units. You can download the import template in Reporting Units, and then follow the Requirements for Template-based Imports discussed in Data Import and Export.
Note: Since you cannot delete reporting units once you import them, you should ensure that the Excel file that you will import is the correct one and that it does not contain any reporting units that you do not want in General Ledger Manager.