Duplicate transaction detection

Rasmerk uses two layers of deduplication to prevent the same SMS from creating multiple transactions.

Layer 1: SMS Message ID

Each SMS has a unique system ID. Rasmerk records (source, messageId) in a local database table after import. If the same SMS ID is seen again, it is skipped.

Layer 2: Raw message body match

Before importing, Rasmerk also checks if a transaction with the same raw SMS body already exists in your records. This catches cases where the same SMS was imported via manual import first, then auto-import runs.

What this means for you

• The same bank SMS will never create duplicate transactions, even if you import manually and auto-import both run.
• If you see what looks like a duplicate, it is likely two separate SMS from the same bank (e.g., debit alert + balance alert), or two transactions at the exact same amount.