View this video at https://macmost.com/creating-a-billing-and-invoicing-system-in-numbers-2025.html. When building Numbers spreadsheets it is important to remember that a row in a table is the equivalent to a record in a database. To build a billing system, you can put clients in one table and invoice items such as billable hours in another table. Then you can build a sheet with tables that use functions to populate an invoice. You can use the new FILTER function for this.