While Omnisend automatically syncs contact data from your store, you can also import contacts manually from a file. Use a CSV or Excel file to add historical subscribers, update existing contact details, or migrate your audience from another platform.

Prepare Your File

To import your contact lists into Omnisend, we recommend using our downloadable example file, which is optimized for the import flow and automatically maps all fields.

If you choose to use your own file, please review the points listed below.

💡 Tip: You can download the example file in the first import step.

When using your own files, you need to change the format of the fields before uploading the file to Omnisend:

File format: The file must be in .csv, .xls, .xlsx, or .ods format and contain only one sheet.
Header row: The first row should include column headings (not contact data).
Contact properties: A single file can contain up to 200 contact properties, with each column representing one property. For more, split your data into multiple files.
One row per contact: Each row must contain all data for a single contact. Each column should include only one type of information (e.g., First name, Last name, City).
Required identifiers: Each contact must include either an email address or a phone number.
Phone number format: Use international format (e.g., +11234567890). To prevent Excel from misinterpreting it as a formula, prefix the number with an apostrophe ('+1...) or change the cell format to Text.
Timestamps: Use ISO 8601 format for dates and times (e.g., 2020-02-29T14:23Z). Dates without a time default to 12:00 PM. Future-dated opt-in or opt-out timestamps won’t be saved.
Address field: Omnisend only supports one Address field. If your file includes separate Address 1 and Address 2 values, combine them into a single comma-separated string: Address 1, Address 2.

The information for import should be recorded in a table similar to the one presented below ⤵️

Once you're finished setting up your file, follow the steps below to import the contact successfully.

💡 You can also import your contacts using the Paste contact details option. This allows you to import up to 500 contacts simply by pasting their information.

Import From a File

To import your contacts from the file, go to the Audience → Contacts → click on the Add or update contacts button → Import contacts from a file → Select file.

You can also add or update contacts from Audience → Imports.

The import process consists of the following steps:

Step 1. Upload File

Upload the file containing the contacts you want to import. If you haven’t prepared it yet, refer to the file requirements and formatting tips listed above.

Step 2. Map Properties

In the drop-down menu, you can choose the mapping for the properties in the file.

The list of fields you can map includes both default and custom properties. If you can find the default field, it is better to use it instead of creating a custom one.

Note: When mapping your properties, ensure that you select the checkbox for the data you want to import. Customer data will only be imported into Omnisend if the corresponding checkbox is checked.

⚠️ Any unchecked data will not be uploaded.

Default Properties

Default properties are the standard contact fields already available in Omnisend. During mapping, you can select them from the drop-down menu.

Default properties include:

Personal data: Email address, Phone number, First name, Last name, Birthdate, Gender.
Address: City, State/Province/Region, Country, Country code, Postal/Zip code.
Opt-in status: Email opt-in date, Email opt-out date, SMS opt-in date, SMS opt-out date.

Important! If you map an opt-out date that is later than the opt-in date, the contact will be imported with an unsubscribed status.

Custom Properties

Custom property (some specific information about your contacts you would like to keep, like their clothes size, preferred newsreader type, etc.).

You can either select an existing custom property or click Create New to add a new property.

Note: Custom property names must follow these rules:

Only Latin characters, numbers, and the underscore (_) are allowed
Maximum length is 128 characters
Names are case-sensitive

After you map all fields and click Continue, any newly created custom properties will become available in forms, contact profiles, and segmentation, among other areas. Read more about custom properties here.

💡Tip: If your file includes both email address and phone number, it’s best to map them as default properties, not custom ones. If mapped as custom properties, they will not trigger automation workflows.

For your first import, we recommend mapping all available properties. If you already have customer details in Omnisend and only want to add your contacts to a segment, it is enough to map only the email address or phone number.

💡Tip: If you want to import a list of tags to Omnisend, you can use custom properties as an alternative.

Step 3. Organize

In this step, you can choose whether to add a tag or create a segment for the imported contacts.

Add Tags

When you import contacts, Omnisend automatically adds two tags:

source: manual import
imported from a file on DD/MM/YY HH:MM:SS
Example: imported from a file on 27/03/20 09:57:05 AM

In addition to the automatic tags, you can also add your own tag by selecting an existing tag or creating a new one.

You can add as many tags as you want. Tags help you filter and segment contacts later, which is useful for more targeted communication.

Create a Segment of Imported Contacts

Although you can always create a segment later based on the tags added during import, you can also create a segment immediately based on:

Import date and time: The segment will be named Contacts imported via <manual_import_type> on <date_of_import>.
Custom name: The segment will appear under Audience → Segments with the name you choose.

Note: You can only create a new segment for a new import. You will not be able to select an existing segment during the import process.

Step 4. Subscribe

In this step, you can choose whether to import your contacts as subscribers or with an undefined (non-subscribed) status.

If your file includes email addresses or phone numbers but does not include a field that defines opt-in status, you can manually select the subscription status for the Email and SMS channels during import.

If either of the checkboxes is left unchecked, contacts will be imported as non-subscribed.

Non-subscribed contacts are typically customers who placed an order, abandoned a cart, or created an account, but never agreed to receive marketing messages. Importing contacts as non-subscribed has the following benefits:

All customer data stays in one place.
We ensure you do not send marketing messages to contacts who never subscribed (transactional messages can still be sent).

Step 5. Finalize

Here, you can choose how to handle duplicate contacts (the ones already in your Omnisend audience) by updating their properties and subscription status, and decide whether to overwrite existing data with empty fields.

Update subscription status and contacts’ properties (Recommended): This option updates both the subscription status and any mapped contact properties in the import file.
Update contacts’ properties only: This updates only the mapped contact details (e.g., name, phone number, etc.) but keeps the existing subscription status unchanged.
Update subscription status only: This updates the subscription status while keeping all other contact details as they are.
Do nothing: This option prevents any changes to existing contacts. Only new contacts will be imported.

Empty Fields Handling

If a repeating contact in your file has missing values in some fields, you can choose whether or not to clear existing data in those fields:

Overwrite with empty fields
- If enabled, any fields left blank in the import file will clear the corresponding existing values for the contact.
- If disabled (default), existing values remain unchanged even if the import file has blank fields.

After configuring these settings, click Continue to Review to verify your import details before finalizing the process.

Step 6. Review

In the last step, you’ll see a summary of your file import. This includes the number of contacts found, the tags and segments that will be assigned, and the selected subscription statuses.

After you start the import, you can track its progress in Audience → Imports.

Click View to see the detailed report which shows the number of new and existing contacts added and the number of good/bad emails/phone numbers found.

Your import is now complete, and you can start sending messages to your imported contacts.

⚠️ If non-Latin characters display incorrectly, save the .csv file in UTF-8 format and upload your contacts again.

Update Existing Customers' Data

If you want to add more information to your customers’ profiles, you can import a file with new or updated data. Ensure the file includes each contact’s email address or phone number so Omnisend can accurately identify them. You don’t need to include all existing customer information in the file.

Important: If you are importing contacts with both an email and a phone number, any duplicate in either field will cause that contact to be skipped.

For example:

[email protected] + (123) 456-7890 → ✅ Imported
[email protected] + (555) 123-4567 → ❌ Skipped (duplicate email found)
[email protected] + (123) 456-7890 → ❌ Skipped (duplicate phone number found)

To ensure that all contacts are imported correctly, check your file for duplicates before uploading.

Omnisend doesn't duplicate your contacts but only adds new information to the system. Therefore, if you need to update your customers' data without changing their subscription status (from non-subscribed or unsubscribed to subscribed), uncheck the checkbox and import your customers with a non-subscribed status.

In that case, your customers' data is updated in the following way:

	Email	Name	Last name	Phone number
Information you have in Omnisend	[email protected]	Kath	Smith	No phone number
New File	[email protected]	Kath	Wood	+14049638495
Result	[email protected]	Kath	Wood	+14049638495

FAQ

What's the difference between file import and store sync?

Store sync automatically and continuously syncs contacts acquired through your store from orders, cart activity, account registrations, etc. On the other hand, file import is a manual, one-time upload for historical data, migrations from other platforms, or bulk updates to existing contacts.

Why is my phone number import failing?

Phone numbers must be in international format: +[country code][number] (e.g., +14255551212). In Excel, you need to format cells as Text or add an apostrophe before the + to prevent Excel from treating it as a formula.

Why didn't all contacts from my file get imported?

Contacts may fail to import for the following reasons:

Some rows are missing an email address or phone number (each contact must have at least one).
Your file contains duplicate email addresses or phone numbers.
The email address or phone number already exists in your audience. In this case, the contact is updated instead of being added as a new contact.

Check your import report in Audience → Imports → View to see a detailed breakdown.

Can I import the same contact list twice without creating duplicates?
Yes. Omnisend doesn't create duplicate contacts. When you import a file with contacts that already exist (matching email or phone number), the system updates their information instead. During the Finalize step, you can choose how to handle existing contacts.

Why didn't my data import even though I mapped the fields correctly?

During the Map Properties step, each field has an import checkbox. Data only imports if this checkbox is checked. Go back to the Map Properties step and make sure all checkboxes under the import column are checked for the data you want to import.