Updating your CSV lets you overwrite incorrect values, remove unwanted data, or correct fields that were placed in the wrong columns. Once re‑imported, the mapped fields are updated in your account, and your corrected details are available straight away for personalisation, segmentation, and automation.
Before you start
Back up your data first.
Export your existing contacts to a CSV file before you make any changes, so you have a copy to restore from.Fixing only a few fields?
Create a CSV with only the Email column and the fields you want to update. Only the fields you map are overwritten.Identifiers aren't overwritten.
Re‑importing doesn't change contact identifier fields, such as email address or mobile number.
1. Edit your CSV file
Open your CSV in Excel or another editor.
Find the columns that were mapped incorrectly.
Adjust the data as needed:
Correct any values that were placed in the wrong column.
Move or rename the column headers so they match the Dotdigital Marketing data fields you intend to map.
Save your file in CSV format.
To remove values from a data field, leave the cells blank and map the column during import. You must also choose Update all data fields in the import settings.
2. Import your corrected CSV file
Go to Audience > Contacts.
Select Import contacts.
Choose your updated CSV file.
For Encoding type, choose Unicode (UTF‑8).
Continue to the Data mapping step.
3. Map your data fields correctly
During the mapping step:
Map each CSV column to the correct Dotdigital Marketing data field.
Map Email to Email Address so Marketing can match and update existing contacts.
If you see columns you don’t want to update, set them to Skip column.
Correct mapping ensures that only the fields you specify are updated and prevents accidental data changes in other fields.