As you mentioned, the easiest way to do this would be to use the “time slips” table itself as the line items table.
However, if you wanted to duplicate these line items into a different “Line Items” table when you’re ready to bill your clients, you could create an automation (using Airtable’s native built-in automations) that creates a new record in the “Line Items” table whenever you check a checkbox on one of the time slip records. It doesn’t need to be a checkbox, but that’s the easiest.
After you’ve got all your line items in your Line Items table ready to attach to an invoice in the Invoices table, you would need to manually link each line item (unless you automate the linking process by writing your own custom JavaScript or by using an external automation platform like Integromat.)
Outside of creating a custom automation like that, the process would be a manual one.
So whenever you are ready to add your line items onto an invoice, you would manually link each line item to an invoice, one record at a time.
You could do this from either the invoice table or the line items table, and that’s because whenever you create a linked record field in Airtable, a “reverse” linked record field is automatically created in the other table.
From the invoice table, you could limit your line item record selection to a view, meaning that if you create a new view in your line items table that only shows you “unbilled” line items, only those line items will show up in your list of line items to choose from.
Hope this helps!
