Note: these steps are only required for Feed Bot sheets (sheets created before August 26, 2019) and some Microsoft Excel workbooks created before Jan 30, 2022.
Use these steps to add the Account ID column to your Balance History sheet, fill in a balance entry with the new ID, and manually backfill old entries with the Account ID.
Open your spreadsheet
Open the Balance History sheet (if you don't see it, open the View menu > Hidden Sheets to unhide it)
Unhide any columns in the Balance History sheet to double check that the Account ID column is not already there.
If the Account ID column isn't in the Balance History sheet already, insert a column to the right of the last visible column (right click and choose Insert 1 right)
Enter Account ID for the header (row 1) for the new column
Visit the Tiller Console at https://my.tillerhq.com/
Click Account Summary and click the pencil icon next to each account in the account summary and then save (click the check mark) - this generates a Balance History update that will have the Account ID
Navigate back to the spreadsheet review the Balance History sheet to make sure the Account ID populated for the accounts.
Unhide the Index column if you don't see it in your Balance History sheet.
Turn on the filter for the entire Balance History sheet (just check the box for "don't show this for 5 minutes" and click okay for any warnings about editing the sheet)
Sort and filter the Balance History sheet by the Account # column and/or Index column.
Copy the Account ID for each account and paste it into the Account ID cell for each historical entry for each unique account to ensure all the prior entries for the account also have the Account ID.
If you notice that a single account has multiple index numbers assigned to this, that indicates that at some point you removed the account from the Tiller Console (perhaps trying to troubleshoot a connection issue) and re-added the account and so it was assigned a new index number. Just re-use the same Account ID associated with the account for this older entries with duplicate index numbers.