File layout
Export one sheet as a comma-separated .csv file using UTF-8 encoding. The upload screen currently accepts CSV only; convert Excel workbooks before selecting them.
- Put clear, unique, non-empty column headers in the first row.
- Use one data record per row and the same columns throughout.
- Quote cells containing commas, quotes or line breaks using normal CSV escaping. The import parser supports quoted cells, but the small mapping preview can display quoted commas or multiline values incorrectly; use the pre-flight result and a small trial import to check the actual data.
- Keep identifiers, postcodes and phone numbers as text in your spreadsheet to preserve leading zeroes and
+signs. - Keep monetary values plain, without currency symbols or thousands separators; provide currency separately where required.
The current upload screen does not enforce a documented numeric file-size or row-count limit. It reads the file into browser memory for preview and pre-flight checking, so split a very large export into manageable files and test a small sample first. This is not a guarantee that arbitrarily large files will process.
Dates
At Pre-flight check, confirm How are dates written in this file? when date fields are mapped:
| Choice | Example |
|---|---|
| dd/mm/yyyy | 31/12/2026 |
| mm/dd/yyyy | 12/31/2026 |
| ISO8601 | 2026-12-31 or 2026-12-31T23:59:59Z |
The initial choice comes from your language settings. Check it against the file: 03/04/2026 is ambiguous. The setting applies to all mapped date fields; do not mix day-first and month-first dates. Changing the choice reruns pre-flight checks. For timestamp fields, retain the time and timezone in the source rather than replacing them with a date alone.
Phone numbers
The contact importer stores Phone and Mobile as text and does not require or automatically convert them to E.164. Use a consistent format, preferably including the country code for international numbers, and verify the spreadsheet has not removed a leading zero. Do not assume import will validate whether a number is diallable.
Small contact example
Copy this into a UTF-8 file named contacts.csv. Use sample data only in a workspace where test records are appropriate.
First Name,Last Name,Email Address,Phone
Alex,Example,alex@example.com,+442079460123
Sam,Example,sam@example.com,02079460124
Map these headers to First Name, Last Name, Email Address and Phone. For other entities, build a header row from Supported entity types and fields. Include stable source IDs as External Keys when you need repeatable matching.
See Run an import.