Postcode validation
Postcode validation is the process of verifying that a delivery address contains a valid Australian postcode that corresponds to the listed suburb and state. In direct mail, this is a critical step — postcards sent to incorrectly formatted or non-existent addresses are wasted spend.
Why postcode validation matters for direct mail
Australia has approximately 2,600 postcode areas across 8 states and territories. Each suburb-postcode combination must be consistent: you can't send mail to "Sydney NSW 3000" (3000 is Melbourne) or to a postcode that doesn't exist. Address errors that slip through validation result in undelivered mail — a cost with zero chance of return.
Beyond format errors, some Australian address types are not deliverable by Print Post: parcel lockers (a PO Box-like Australia Post service), parcel collect points, and locked bag addresses don't accept addressed marketing mail.
What TouchDrop validates
- Postcode-suburb-state consistency — The suburb and state must correspond to the postcode
- Parcel locker filtering — Addresses identified as parcel lockers are excluded (they won't accept Print Post mail)
- Parcel collect filtering — Similar exclusion for Australia Post's parcel collect service addresses
- Street number and name formatting — Basic format checks to catch obvious data entry errors
Where address data comes from
In TouchDrop, address data comes from Shopify's customer and order records. The shipping address customers enter at checkout is used as the postcard delivery address. TouchDrop validates this data at the point of campaign audience assembly — before the postcard is queued for print — so invalid addresses are filtered without incurring a print cost.
Related terms and reading
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