What file format does an import accept?

Property	Accepted value
File type	.csv, .tsv, or .txt
Separator	Comma, semicolon, or tab
Encoding	UTF-8
Maximum file size	10 MB
Maximum rows	50,000, including the heading row
Maximum columns	251, including the email column
Preview	First 10 rows

Pasted spreadsheet rows use the same parser and limits.

Prepare the file

1. Export the spreadsheet as CSV UTF-8.
2. Keep one email-address column.
3. Put field names in the first row.
4. Remove columns you will not use.
5. Keep the file within the limits above.

Quoted separators, quoted line breaks, doubled quotes, Windows line endings, and a byte-order mark are accepted. Blank rows are discarded, but row numbers in a skipped-rows report still count them.

If your file is refused

Problem	What to do
File is larger than 10 MB	Split it into smaller files
More than 50,000 rows	Split it, counting the heading row in each file
More than 251 columns	Remove columns you do not need
No column reads as addresses	Check that the email column is present and not entirely blank
Wrong encoding	Export the file again as CSV UTF-8
Not plain text	Export the spreadsheet or document as CSV first
Unterminated quote	Close the unmatched quote, then upload the file again

If ColdMerge reports too many uploads at once, wait a moment and choose the file again. Nothing from the refused file was staged.

Choose a separator

Detect automatically examines the start of the file and chooses comma, semicolon, or tab. If the preview is wrong, return to Upload, choose the separator yourself, and select Read the rows again.

Email rules

ColdMerge detects the email column from its values, not only its heading. During import it trims surrounding whitespace, lowercases the address, and treats case variants as the same contact.

The address must contain one @, a dotted domain, no spaces or control characters, and no more than 254 characters.

Field rules

• firstName and lastName are the standard field names.
• The built-in {{email}} token makes a custom email field unnecessary.
• A field name can contain at most 120 characters.
• Names containing |, {, }, or a line break cannot be merge tokens and are refused at mapping.
• Two columns cannot map to the same field.

When a heading matches an existing Organization field without regard to case, the existing spelling wins. A later import updates the fields it supplies and leaves other fields alone.

For the upload steps, see import contacts.

For row outcomes and the skipped-rows download, see import results and history.