What is a CSV file? Definition, features, and importance in 2025

CSV files are one of the simplest ways to organize and share data. Let’s break down what a CSV file is, why it matters for your business, and how tools like QuickBooks make it even easier to work with your data.

Jump to:

• Key characteristics of a CSV file
• How CSV files are used in business and data management
• Creating and opening CSV files
• Advantages and limitations of CSV Files
• CSV files and QuickBooks

CSV file definition

CSV stands for Comma-Separated Values. It’s a simple file format that helps you store data—e.g., names, numbers, or dates—in a table-like structure. Each line in a CSV file is a row, and each value in that row is separated by a delimiter—i.e., a special character. This is typically a comma, but other delimiters, such as semicolons or tabs, may also be used.

Purpose of a CSV file

The purpose of a CSV file is to provide a simple, universal format for exchanging data between different applications, such as spreadsheets, databases, and software platforms. Because it's plain text, you can open and edit a CSV file using a variety of tools, including Microsoft Excel, Google Sheets, and even basic text editors like Notepad or TextEdit.

Structure of a CSV File

CSV files organize data in a simple, easy-to-read format. Like a spreadsheet, they use just rows and columns.

Here’s how it’s typically structured:

• Each row represents one record: This could be anything—e.g., a customer’s details, a product entry, or a line from a transaction list.
• Each value in the row is separated by a delimiter: Commas are the most common, but other characters like semicolons, tabs, or pipes might be used.
• The first row usually contains headers: These are the column names that label the data, such as name, email, or phone number.

See the example below to get an idea of how it might look:

Name,Email,Phone

John Jones,john@email.com,555-555-5555

Jane Jones,jane@email.com,777-777-7777

In this example, each line is a separate record, each value is split by a comma, and the structure stays consistent, so the software knows how to read it.

Key characteristics of CSV files

Let’s take a look at the key features that make them a popular choice for storing and sharing data:

Plain-text format

CSV files are made of plain text only. That means they don’t include any formatting, like bold fonts, cell colors, or column widths. It’s just raw data.

Because of this, both people and machines can easily read them. You can open a CSV in a text editor like Notepad or TextEdit and see the entire file without needing special software.

Simplicity

The structure of a CSV file is straightforward: rows and columns are separated by a single character. There’s no code, tags, or complicated formatting. This simplicity makes CSVs easy to create and less likely to cause problems when moving data between tools.

Universal compatibility

CSV files work just about everywhere. You can open them in spreadsheet tools like Excel or Google Sheets, load them into databases, or use them with most programming languages.

They’re also supported across all major operating systems—e.g., Windows, macOS, Linux—and can be opened in nearly any text editor or data tool. This universal compatibility is a big reason why businesses rely on them to move data between platforms.

Delimiters

Even though they’re called “comma-separated,” commas aren’t the only option. Other delimiters—e.g., semicolons, tabs, or pipes—can also be used, especially in places where commas are already used as decimal points (like much of Europe). It all works the same as long as everything stays consistent.

How CSV files are used in business and data management

Here’s how businesses can use CSV files for everyday operations:

Data exchange 

CSV files act like a bridge between systems. Whether you’re moving customer lists from a CRM into an email marketing tool or sending sales numbers from your e-commerce store to your accounting software, CSVs help you transfer that data without losing structure or compatibility. Their plain-text format makes it easy for different tools to understand and work together.

Importing and exporting data

Need to update a product catalog, load a list of vendors, or export your sales history for review? CSV files are built for these kinds of bulk tasks.

You can use them to:

• Import new inventories into e-commerce tools
• Add or update customer details in bulk
• Export financial records or order histories for reporting or backups

Ultimately, they’re a quick way to handle a lot of data without doing it all by hand.

Database interaction

Businesses commonly use CSV files to load data into databases or to export query results for use elsewhere. For example, your business might use a CSV to import raw sales data into a reporting database or pull data out to analyze trends in a spreadsheet.

Reporting and analysis

When it’s time to dig into the numbers, CSVs give you a clean slate. They open quickly in tools like Excel or Google Sheets, and they don’t come with extra formatting that can get in the way.

This makes them perfect for:

• Building custom pivot tables
• Sorting or filtering data
• Running simple calculations
• Combining data from multiple sources

Creating and opening CSV files

CSV files are simple to work with, whether you're opening one, editing it, or importing it into your favorite tool. Here’s a step-by-step guide for each method:

Using spreadsheet software

Most people use spreadsheet programs like Microsoft Excel or Google Sheets to open and edit CSV files. Here’s how to open and create it in your software of choice:

To open a CSV file:

1. Open your spreadsheet program (e.g., Excel or Google Sheets)
2. Go to File > Open.
3. Select the CSV file from your computer.
4. The file will load with each line as a row and each comma-separated value in its own cell.

To create and save a CSV file:

1. Create your data as you would in a normal spreadsheet.
2. When you’re ready to save it, go to File > Save As (or Download As in Google Sheets).
3. Choose CSV (.csv) as the file format.
4. Name your file and click Save.

Using text editors

Because CSV files are plain text, you can also open them in basic text editors like Notepad (Windows), TextEdit (Mac), or VS Code. This is helpful when you need to check for errors, fix the formatting, or edit on a system without spreadsheet software.

To view or edit a CSV in a text editor:

1. Right-click the file on your computer.
2. Choose Open With, then select your text editor.
3. You’ll see each row as a line of text, with values separated by commas (or another delimiter).

Importing into applications

Many apps—like QuickBooks, email marketing platforms, and CRM tools—let you import CSV files to save time on manual entry. Each tool is a little different, but the flow is usually the same.

To import a CSV file into an application:

1. Log into the app and go to the import or upload section.
2. Choose your CSV file from your computer.
3. The app may ask you to:

• Confirm the delimiter (comma, semicolon, tab, etc.)
• Map your columns to the fields used in the app
• Preview how the data will look before completing the import

Once everything looks right, click Import or Upload.

Advantages and limitations of CSV Files

CSV files are useful, but they’re not perfect for every situation. Here’s a look at what they do well and where they fall short.

Advantages

Some of the benefits of using CSV files include:

• Small file size: Since they’re just plain text, CSV files take up very little space. That makes them fast to open, share, and upload.
• Cross-platform compatibility: You can open a CSV file in Excel, Google Sheets, databases, text editors, and many business applications on any operating system.
• Human-readable: Unlike complex file types, CSVs are easy to read. You can open one in a text editor and instantly see what’s inside.
• Easy to create and parse: Whether you’re typing up a list in a spreadsheet or having a tool export your data, generating a CSV is quick and straightforward. If you’re a developer, they’re also easy to parse in code.

Limitations

CSVs also have some downsides, especially if your data or workflow is more complex. Here are some drawbacks:

• No formatting: CSV files don’t support fonts, colors, bolding, or any type of styling.
• No formulas or macros: You won’t find any advanced features like calculations, pivot tables, or automation inside a CSV.
• No multiple sheets: Unlike Excel workbooks, a CSV can only hold one sheet of data.
• Challenges with special characters: If your data includes commas, line breaks, or quotes, you’ll need to escape them properly, or your file might not load correctly.
• No built-in data types: A CSV doesn’t tell the software what’s a date, a number, or plain text. It leaves that up to the program, which can sometimes guess wrong.
• Not ideal for large datasets: If you're working with massive datasets, a database or binary format like Parquet may perform better than a flat CSV file.

CSV files and QuickBooks

QuickBooks makes it easy to use CSV files to manage and move your business’s financial data. Here’s how CSV files work inside QuickBooks:

Importing bank transactions

One of the most common uses of CSV files in QuickBooks is importing bank or credit card transactions. If your bank doesn’t connect directly to QuickBooks, you can:

1. Download your statement as a CSV file from your bank’s website.
2. Upload that CSV into QuickBooks Online.
3. Use QuickBooks to match, categorize, and reconcile those transactions quickly.

This helps keep your books up to date without having to enter each transaction by hand.

Importing lists

CSV files also help you set up or update large amounts of business data in just a few clicks. You can import lists like:

• Customers and vendors
• Products and services
• Your chart of accounts

Instead of adding each entry one by one, you just fill out a CSV file with the info, upload it, and let QuickBooks handle the rest. This is especially helpful when switching to QuickBooks for the first time or making big updates to your records.

Exporting reports for custom analysis 

Need to dig deeper into your numbers? You can export many QuickBooks reports to a CSV file for custom analysis.

From there, you can:

• Open the file in Excel or Google Sheets.
• Build your own pivot tables.
• Combine it with data from other sources.
• Share the data with accountants, analysts, or your team.

With CSV support built into key features, QuickBooks helps you avoid manual entry, cut down on errors, save time on data management, and keep your books organized.

The enduring utility of CSV files

CSV files may be simple, but their value has stood the test of time as they continue to offer a reliable way to store, share, and manage structured data.

And when you need to work with CSV files, QuickBooks makes it easy. Our accounting software gives you the tools to import, export, and manage your financial data all in one place.