You have the option to sync historical transactions for the specified date range to Xero by using the "Sync older transactions" feature. This feature ensures that duplicate transactions are prevented from appearing on Xero by deduplicating the transactions. You will have the ability to specify the currency, start date, and end date for a period of up to 365 days prior to the current date.
- Transactions that occurred before your feed was first activated will not be automatically synced to Xero
Syncing transactions that are older than 365 days from the current date is not feasible, as Xero's system only supports transactions within the past 365 days (Xero documentation)