Format a CSV File for Import
Last updated on Sep 19, 2026
The importing functionality makes data changes based on the CSV file you provide. Therefore, the files must be formatted correctly in order for the import to complete successfully. Take care when editing the file as mistakes can have unintended consequences.
Preparing the CSV file
The spreadsheet you create contains the data used to augment the affected objects and corresponding fields during the import. Each row in the CSV represents an object and each column represents a field. For example, if you are performing a customer import, then each row of the CSV represents an individual customer and the columns represent the customers' fields.
Field types
The system supports five types of importable field data.
| Field | Description |
|---|---|
| Alphanumeric | A mix of text and/or numbers |
| Number | All number records in your CSV for a single column must use the same format. Do not use currency symbols or separators such as commas and periods. Improper formats:
|
| Date | All date fields must use the same format and match the format selected in your Map. Supported date formats:
|
A field that accepts one or more email addresses, such as a Customer's Email, CC Email, or Escalation Email. Separate multiple addresses with commas or semicolons; either delimiter is accepted and semicolons are automatically converted to commas on import. Any other delimiter, for example a pipe, is not recognized, and the row is rejected as invalid. A semicolon inside a quoted local part, such as "a;b"@example.com, is preserved rather than treated as a delimiter. | |
| Binary | Binary fields can be imported or defined in the map itself. A CSV file accepts True or Yes for a true value, and False or No for a false value. Capitalization does not matter. The import map presents the same values as Yes and No when you select to input a value directly. |
| A field that accepts one or more email addresses, such as a Customer's Email, CC Email, or Escalation Email. Separate multiple addresses with commas or semicolons; either delimiter is accepted and semicolons are automatically converted to commas on import. Any other delimiter (for example, a pipe) is not recognized, and the row is rejected as invalid. |
Required fields
You must have valid data in the CSV for any Maxio required fields when performing an import. Rather than building the header row manually, export the object's existing records and use that file as your template, which guarantees the column names match what the importer expects.
To generate a CSV template in Maxio
-
Navigate to the page of the object you are importing. For example, open the Customers page if you are importing customers.
-
Hover over the Download button and select either Export Displayed Columns - Download or Export All Columns - Download. The menu also offers Google Sheets versions of both, which save to a Google Sheet instead of downloading a file.
-
The CSV file then downloads to your computer. Open the file to view the spreadsheet and use it as the basis for a new import file.
Convert to CSV UTF-8
The import requires CSV files saved with UTF-8 encoding. A byte order mark is fine, since the importer strips it when it reads the file. Generating the file correctly requires different steps depending on which spreadsheet software you are using to prepare the data, and on which operating system.
- Excel for Windows: When saving, select CSV as the file type. Then, click the Tools button in the bottom right and select Web Options. Open the Encoding tab and then select the UTF-8 option.
- Excel for Mac: Select the Windows Comma Separated Values format when saving the file.
- Numbers for Mac: Click File > Export To and then select the CSV option. Expand Advanced Options to confirm the Unicode (UTF-8) option is selected.
CSV file clean-up
Once the file is in the correct format, it likely requires clean-up to correct any remaining errors. The majority of import issues that users experience have to do with improperly formatted CSV files. Excel rarely produces a completely correct UTF-8 file, because of the various versions of the software running on equally varying versions of Windows and Mac. To avoid errors, perform some final clean-up in the file to guarantee it is ready for importing.
You should avoid editing the CSV file further in Excel once you have converted it, so you must perform this clean-up step using a text editor. We recommend Notepad++ on Windows and BBEdit on macOS. You can then check for the following common issues:
-
Bad Characters: Many text editors contain functionality for removing bad characters. This is important as bad characters may not display in Excel. In the example below, the first row of the import contains a bad character in the Number column. You can see it in the text editor, but not in Excel.
-
Extra Rows: A text editor should also allow you to identify extra rows and columns more easily as they display as extra commas.
-
Trailing Spaces: Be aware of trailing spaces as they can create duplicate records.
-
Column Headers: Each column header must have a unique name. Blank or null headers are also not permitted.
-
Leftover Errors Column: If you're reusing a CSV that was previously exported as a failed import's results, remove any column named Errors before uploading. Maxio carries that column's values through unchanged into the new run, and old failure text sitting next to the new run's own status can look like the current import failed even when it succeeded. See Run an Import for the warning Maxio shows if it detects this column.
Once the file is ready, you can proceed with executing the import in Maxio.
Related information
To see which import types are available and what each one changes, see Understand Imports.
To upload your finished file and read the results, see Run an Import.
Still need help?
Reach out and our support team will take it from here.