Excel CSV Import Problems? Fix Dates, Delimiters & More

For most Excel CSV import problems, avoid opening the file by double-clicking it. In Excel for Microsoft 365 on Windows, choose Data > From Text/CSV, check the delimiter and preview, set sensitive columns such as dates or ID codes to the correct type, then select Load.

Why CSV files behave differently in Excel

A CSV file stores rows of text separated by a delimiter, usually commas. It does not store workbook features such as multiple sheets, cell formats, formulas as formulas, or reliable instructions about whether a value is a date, number, or identifier. Excel must interpret the text when it opens or imports the file. That interpretation can depend on regional settings, the file’s encoding, and Excel’s automatic type detection.

This is why a file that looks correct in a text editor can appear wrong in a worksheet. For example, an entry such as 03/04/2025 could mean March 4 or April 3, depending on the date convention. A value such as 00127 may be interpreted as the number 127, while a long account number may be rounded if Excel treats it as a numeric value.

CSV is useful for exchanging plain tabular data between applications, but it is not a dependable way to preserve how Excel displays or types that data. If you need to keep Excel-specific formatting and types, import the data and save the result as an .xlsx workbook.

Import a CSV without relying on automatic guesses

On Windows, use Excel’s text import rather than opening the CSV directly. The preview lets you catch many problems before they enter the worksheet, and Power Query provides controls for setting column types.

Open a blank workbook or the workbook where the data belongs, then select Data > From Text/CSV.
Browse to the CSV file and select Import. Check the preview for the right delimiter, correct column boundaries, and readable characters.
If the columns or characters look wrong, adjust the delimiter or file origin in the preview. Choose Transform Data if you need to control data types before loading.
In Power Query, select a column and set its data type using the data type menu. Choose Text for identifiers, postal codes, and other values that must retain leading zeros or exact digits.
Select Home > Close & Load to put the data in Excel. Review the loaded result before using it in reports or calculations.

Excel for Mac also offers text and Power Query import options, but the labels and available controls can differ by version. Look under the Data tab for Get Data (Power Query) or a text/CSV import command. Excel for the web has fewer desktop import and transformation controls, so use the desktop app when you need precise type handling.

Fix columns that split incorrectly

If an entire row appears in one column, or names and addresses break into unexpected columns, Excel may be using the wrong delimiter. A comma is common, but files can use semicolons, tabs, or another character. Regional settings can also affect how Excel interprets separators when a file is opened directly.

In the From Text/CSV preview, choose the delimiter that matches the file. If the data is separated by semicolons, for example, select semicolon rather than comma. The preview should show each field in its own column, with headings and records aligned. If the file uses a less common separator, check the source system’s export settings or inspect a copy in a plain-text editor.

Do not split on a comma simply because the file is called comma-separated. A correctly formatted CSV can contain commas inside a field when that field is enclosed in quotation marks. For instance, a quoted address such as 18 Oak Street, Unit 4 is one value, not two columns. Excel’s CSV parser should respect that quoting; manually splitting every comma can damage the data.

Handle quotation marks and broken rows

CSV uses quotation marks to protect delimiters and line breaks that belong inside a field. A quote inside a quoted field is commonly represented by two consecutive quotation marks. If a source file has unmatched quotes or inconsistent escaping, Excel may combine multiple lines into one record or shift values into the wrong columns.

When only a few rows look damaged, compare them with the original file in a plain-text editor and check whether quotation marks are balanced. If the export comes from a database or business system, re-export it with a standard CSV option rather than trying to repair a large file by hand. Avoid using Find and Replace to remove all quotation marks: some of them may be essential to keeping commas inside a field.

A CSV file can also contain line breaks inside a properly quoted field, such as a multi-line note. Those line breaks are part of the cell value, not necessarily signs of a broken row. Check the source application’s export rules before deleting them.

Correct garbled characters and encoding

Text such as accented names or non-Latin characters may appear as question marks or strange symbols if Excel reads the file using the wrong character encoding. The file origin setting in the import preview tells Excel how to decode those bytes. For a file exported as UTF-8, select the UTF-8 encoding, often shown as 65001: Unicode (UTF-8), when that choice is available.

Import the file again after changing the encoding; changing the font in the worksheet will not repair text that was decoded incorrectly. If you do not know the encoding, ask the system that produced the CSV or test the likely options on a copy. Avoid saving over the original until you have confirmed that names and symbols display correctly.

For future exports, UTF-8 is a widely used choice for multilingual text, but the receiving application still needs to read it as UTF-8. If another system requires a different encoding, follow that system’s requirements and keep an untouched source copy.

Stop dates from changing or becoming ambiguous

Excel may automatically convert text that resembles a date into a date value. That can change the display, and the interpretation of a value such as 04/05/2025 can vary by regional date convention. A conversion can also be difficult to reverse if the original text is no longer available.

If a column must remain exactly as written, set it to Text in Power Query before loading. If it represents genuine dates, confirm the source’s date order first. When a value contains day, month, and year but Excel reads it using the wrong regional convention, Power Query can convert the selected column using a locale: right-click the column, choose Change Type > Using Locale, then select the appropriate date type and locale.

Do not fix ambiguous dates by changing the displayed cell format alone. Formatting changes how a recognized date appears; it does not reliably change the order Excel originally assigned to the day and month. Re-import from the original CSV if Excel has already interpreted the values incorrectly.

Preserve leading zeros and long identifiers

Postal codes, product codes, telephone numbers, and account IDs may look numeric but are identifiers, not quantities. If Excel imports 00127 as a number, it stores 127 and drops the zeros. Set that column to Text during import to preserve the original characters. Applying a custom number format afterward may make zeros appear again, but it does not restore the original text or suit every identifier.

Long digit strings need special care. Excel retains only 15 significant digits of numeric precision, so a longer identifier imported as a number can lose digits. Once that happens, changing the cell to Text cannot reconstruct the missing digits. Import the column as Text from the start and compare important identifiers with the source file.

On the other hand, amounts and counts that need arithmetic should usually be imported as numbers. The goal is not to set every column to Text; it is to choose a type that matches what the field means and how it will be used.

Understand regional number formats and missing values

A decimal comma and a decimal point are not interchangeable in every locale. A value written as 1.234,56 may represent one thousand two hundred thirty-four and 56 hundredths, while another setting may read the separators differently. If values import as text or become unexpectedly large or small, inspect the file’s number convention before changing the worksheet format.

In Power Query, use Change Type > Using Locale when a numeric column needs to be interpreted according to a specific regional convention. Confirm a few known values against the source. Also check how blank fields, the literal word NULL, and zero values are represented: they are not automatically the same thing, and downstream calculations may treat them differently.

Check the file, then save in the right format

Before relying on an import, compare the number of columns and records with the source, inspect a few rows at the beginning and end, and verify any columns where exact values matter. Check totals only after confirming that numeric fields were parsed correctly. A visually tidy preview does not guarantee that dates or identifiers have the intended meaning.

After the data is correct, save the workbook as an Excel Workbook (.xlsx) if you need to retain types, formatting, formulas, tables, or multiple sheets. Saving as CSV writes plain text for one sheet and discards workbook features. If you must deliver a CSV, check the export options and reopen a separate copy to confirm that the receiving system will interpret its delimiter, encoding, and values correctly.

Safety when importing CSV files

Treat CSV files from unknown sources cautiously. A cell containing text that begins with a formula marker may be interpreted as a formula when opened directly in spreadsheet software. Do not open an unexpected file just because it is a text format, and do not trust a CSV as inert merely because it has no macros.

For sensitive or untrusted data, use a controlled import, set columns that must remain literal to Text, and inspect formula-like values before sharing or processing the workbook. If you need to neutralize such values, do so in a documented preprocessing step and verify that it has not changed legitimate data. Never enable external connections or follow links simply because an imported file prompts you to.

Frequently Asked Questions

Why does Excel put my whole CSV in one column?
Excel is probably using a different delimiter from the one in the file. Choose Data > From Text/CSV and select the delimiter shown in the preview, such as comma, semicolon, or tab.

How do I stop Excel changing 00123 to 123?
Import the relevant column as Text in Power Query before loading. If Excel already removed the zeros, re-import the original CSV; changing the cell format cannot reliably recover the original value.

Why are my CSV dates showing the wrong day and month?
The file may use a date order that differs from your regional settings. Re-import the source and use the correct locale for genuine dates, or select Text if the values must remain unchanged strings.

How do I fix strange symbols in a CSV?
Re-import the file and select the encoding used by its source, commonly UTF-8 for multilingual data. Changing the worksheet font does not fix an encoding mismatch.

Should I open a CSV by double-clicking it?
That is convenient for simple files, but Excel may infer types and separators automatically. Use Data > From Text/CSV when exact dates, identifiers, encoding, or column boundaries matter.

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