If you'd like to use a single spreadsheet to track and manage shared expenses with a spouse, business partner or family member use these steps.
You only need one Tiller account so pick the gmail account you'd like to use to access the Tiller Console.
Use this one account and console to add all accounts that need to be tracked in one or more spreadsheets. You'll need to other person (or people) with you to enter their bank usernames and passwords.
Create up to five Tiller spreadsheets for your various financial tracking needs.
Link the accounts to the appropriate sheets. If you have a shared bank account that appears twice in your Account Summary because you've connected multiple logins to the Tiller Console only link one instance of the account to the spreadsheet otherwise you'll end up with duplicate transactions.
Share the Google Sheet with your partner.
Update the Categories sheet to reflect shared expenses.
Categorize transactions. Check out AutoCat for quick automatic categorization.
Example category setup:
Partner 1 income
Partner 2 income
Partner 1 expenses
Partner 2 expenses
Shared expenses paid by partner 1
Shared expenses paid by partner 2
In the example below we use the first initial in the Category name to differentiate between categories since they must be unique, but both individuals are likely to have the same category of expenses.