Preparing a CSV file
How to prepare a CSV file with the right format, UTF-8 encoding, header row and correct phone numbers for a smooth import.
Last reviewed: 2026-07-22
Preparing a CSV file
A cleanly prepared CSV file is the basis for a smooth import. Take a moment before uploading to check the format, encoding and content. This saves you corrections later.
File format and encoding
- Save the file as CSV.
- Use UTF-8 encoding so that special characters are imported correctly.
- Use a consistent delimiter throughout the file.
Header row and columns
The first line of the file is the header row. It names the columns and serves as the basis for column mapping during import.
- Use clear, easy-to-read column names.
- Create a separate column for each piece of information, such as name, phone number and company.
- Avoid empty column headers and duplicate column names.
Checking the content
- Fill in the required fields in every row. Which fields are required is shown in required and optional contact fields.
- Write phone numbers in international format with a country code.
- Remove records that are clearly invalid or empty.
- Standardize spelling to avoid duplicate contacts.
Hinweis: Format the phone column as text before saving. Otherwise spreadsheet programs may strip leading zeros or the country code.
Before the import
Spot-check a few rows and confirm that the columns match their content. Once the file is prepared, continue with the CSV import.
Common questions
Which delimiter should I use?
What matters is a consistent delimiter throughout the whole file. Avoid mixing different delimiters, otherwise columns are recognized incorrectly.
How many rows may the file contain?
Nexcal does not prescribe a fixed number of rows. For very large files it is advisable to split your base into manageable partial files so you keep control over data quality.
Does every column have to be imported?
No. You can exclude columns you do not need from the import during column mapping. However, make sure the required fields are present and filled in correctly.