We use various methods for preventing duplicates. Cleared (booked) transactions should not be an issue, as each transaction is assigned a unique identifier by our provider and your bank.
Pending transactions can be tricky however, as they do not have a reliable unique identifier. For this reason we have developed our own duplicate filtering engine. The engine uses different combinations of all available data points to determine whether a transaction is a duplicate or not. This works well for most banks, but there might be some banks that offer very little transaction data. In these cases, detecting duplicates can be difficult. Transactions that are actually duplicates may pass through, or transactions that are not duplicates may be filtered out.
If you are struggling with duplicates or missing transactions, you can try to customize the fields we use when filtering duplicate transactions:
This setting is available under Bank Account > Settings > Advanced.
Be careful when using this setting. You should to look through your transaction data to verify that there is a field combination that can be used to filter duplicates. If you set this to the wrong fields, you may get duplicate transactions, or no transactions at all.
If you are unable to use this setting, or are still struggling with duplicates or missing transactions, we recommend disabling pending transactions. This can be done in Bank Account > Settings > Sync.