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CSV Upload - FAQs

What format does thanks.io require?​

UTF-8 encoded with a header row. Each subsequent row is one recipient.

What columns are required?​

A deliverable physical address is required (at minimum: street address and country). Name, city, state/province, and postal code are strongly recommended. Email, phone, and custom fields are optional.

How do I map custom fields?​

The upload column-mapping screen lets you map CSV columns to custom1-custom10. Once mapped, those values are available as %CUSTOM1%-%CUSTOM10% in any creative's message (or the message you write in Send Mail).

Can I preview before uploading?​

Yes. thanks.io shows a preview with sample rows and column mappings before you confirm the import.

What happens to duplicate rows?​

Duplicate rows are imported. Duplicate Prevention then governs whether each recipient receives mail within the 36-hour window. De-duplicate your CSV before uploading for cleaner lists.

Does CSV upload update existing recipients?​

No. Uploading adds new recipients. To update an existing recipient's address or custom fields, edit the recipient directly in the dashboard.

How do I handle international addresses?​

Include a country column with the 2-letter country code (e.g., CA, GB). Follow the postal conventions of the destination country.

How do I add a spouse, second name, or business name to the postage address?​

Use the 2nd Contact field (the CSV column header is company). The value you enter will appear below the recipient's name on the envelope.

You can also reference it in a message using %COMPANY%.

If you want to address both people in the message body (for example, "Dear Bob & Alice"), store the combined name string in a custom field such as custom1, then use %CUSTOM1% in your message.