10 Common CSV Errors and How to Fix Them in 2026

What causes it?

This happens when different rows have different numbers of columns. Common causes include:

• Missing commas (e.g., "John,Doe,30" instead of "John,Doe,,30" when a field is empty)
• Extra commas in data (e.g., "San Francisco, CA" creates an unintended column split)
• Unescaped quotes that break CSV structure
• Manual editing in Excel that removed columns from specific rows

How to fix it:

name,email,city,age
John Doe,john@test.com,New York,28
Jane Smith,jane@test.com,San Francisco,34
Bob Johnson,bob@test.com

Solution: Use our free CSV validator to automatically identify rows with mismatched column counts. The validator will show you exactly which rows are problematic and what the column count should be.

For manual fixes, ensure empty fields are represented by commas: Bob Johnson,bob@test.com,, (note the two trailing commas for empty city and age). Alternatively, use our CSV cleaning tool to fix these issues automatically.

What causes it?

Character encoding mismatches occur when a file is saved in one encoding (e.g., UTF-8) but opened in another (e.g., Windows-1252 or ISO-8859-1). This mangles special characters, accents, and emojis.

How to fix it:

Best practice: Always save CSV files as UTF-8 with BOM (Byte Order Mark). This tells Excel and other tools to use the correct encoding. In Excel: File → Save As → CSV UTF-8.

If your file is already corrupted, use our CSV cleaning tool which automatically detects and converts to UTF-8.

What causes it?

Different regions use different date formats: MM/DD/YYYY (US), DD/MM/YYYY (EU), YYYY-MM-DD (ISO). When these get mixed in a single column, databases and analytics tools can't parse them correctly.

How to fix it:

The ISO 8601 standard (YYYY-MM-DD) is universally unambiguous and sorts correctly. Use our date formatter tool to automatically convert all dates to ISO format.

What causes it?

Email lists often contain typos, incomplete addresses, or placeholder values like "test@test" that break email validation rules.

How to fix it:

Use our email list validator to check syntax and find invalid addresses. For deeper cleaning, try our email list cleaner which also removes duplicates and normalizes domains.

What causes it?

Since CSV uses commas as delimiters, any comma inside a field value (like "San Francisco, CA") must be escaped with quotes. Same for quotes inside values.

How to fix it:

Proper escaping: "Company, Inc." instead of Company, Inc.. Our CSV validator catches these issues automatically.

What causes it?

Copying data from websites, PDFs, or Word documents often introduces invisible characters like tabs (\t), carriage returns (\r), or zero-width spaces.

How to fix it:

Use our CSV cleaner with the whitespace normalization option to remove hidden characters while preserving intentional line breaks.

What causes it?

Merging multiple exports, accidental copy-paste, or database glitches create duplicate rows that skew analytics and waste storage.

How to fix it:

Our duplicate remover can find exact duplicates or identify rows that match on specific key columns (like email or ID). Learn more in our guide on email list hygiene.

What causes it?

Excel formatting, deleted content, or accidental spacebar presses create rows/columns that appear empty but still count as data.

How to fix it:

Use our CSV cleaner to automatically remove empty rows and columns. This reduces file size and prevents import errors.

What causes it?

Different locales use different number formats: US uses commas for thousands (1,234.56), Europe uses dots (1.234,56). Currency symbols and percentage signs also vary.

How to fix it:

Strip all formatting and use plain numbers: 1234.56. Our CSV cleaner has number normalization built-in.

What causes it?

Despite the name "Comma-Separated Values", many CSV files use semicolons (;), tabs (\t), or pipes (|) as delimiters—especially in Europe where commas are decimal separators.

How to fix it:

Most modern tools auto-detect delimiters, but if yours doesn't, use our CSV validator which supports all common delimiters and can convert between them.