Step 1

Identify which Outlook receives the contacts

Microsoft's import and export contacts article gives separate instructions for three experiences: Outlook.com in a browser, new Outlook for Windows, and classic Outlook for Windows. The steps differ, and so do the decisions Outlook asks you to make. If you are unsure which one you use, the same article links to Microsoft's help on finding your Outlook version.

In Outlook.com and new Outlook, Microsoft's documented import is a short flow from the People page: choose a CSV file and select Import. Those steps include no field-mapping screen and no duplicate option. In classic Outlook, the Import and Export wizard asks how to treat duplicates, which folder receives the contacts, and lets you map fields.

Choose the path before preparing the file. In the browser flow, the headings in your file are the mapping, so they must be right before upload. In classic Outlook, you make duplicate and folder decisions inside the wizard. The private Outlook contacts CSV validator changes its review findings to match the path you select.

Step 2

Export the existing contacts first

Before adding anything, export what is already there. Microsoft documents export for each path. In Outlook.com, open People and choose Manage contacts, then Export contacts, pick All contacts or another option, and select Export. In new Outlook, open People, choose Export contacts, pick a folder under Contacts from this folder, and select Export; the file goes to your Downloads folder.

In classic Outlook, choose File, Open & Export, Import/Export, then Export to a file and Comma Separated Values. Microsoft singles out choosing the Contacts folder under your account as the key step, so check it before you name the file.

Microsoft suggests opening the exported file in Excel to verify the contacts are there, notes that many empty cells are normal, and generally recommends closing it without saving changes. Keep that export untouched and separate from the file you will import. It is your comparison point, and it shows the exact headings your Outlook writes.

Step 3

Put Outlook's column headings in the first row

Microsoft's article on creating CSV files to import into Outlook says Outlook requires column headings in the first row and warns not to replace them with something else. It also says the language of the column headings must match Outlook's default language, so English headings are not a safe assumption for an Outlook set to another language.

Microsoft publishes a sample CSV file for importing contacts. Its header row has 92 columns, including First Name, Middle Name, Last Name, Title, Suffix, Company, Department, Job Title, address parts such as Business Street, Business City, Business State, Business Postal Code and Business Country/Region with matching Home and Other sets, phones such as Business Phone, Home Phone and Mobile Phone, E-mail Address, E-mail 2 Address, E-mail 3 Address, Birthday, Anniversary, Categories, Notes and Web Page.

Spelling matters: the email headings use a hyphen in E-mail, and the country headings use Country/Region. You do not need every column. Microsoft says you only enter the information you want, so the validator writes just the fields you mapped, in the sample's column order, and offers the full 92-heading file as a blank template.

Step 4

Map your spreadsheet columns deliberately

Real spreadsheets rarely use Outlook's headings. They say Work Email, Cell, Organization, or Zip. Microsoft's classic Outlook Excel import article shows the Map Custom Fields screen: your CSV column names appear under From, Outlook's fields appear on the right, and a column that matches a field shows as already mapped. Microsoft's example drags a column named Cell Ph onto Mobile Phone.

Microsoft's Outlook.com and new Outlook steps show no mapping screen, so the mapping must live in the file. Renaming each heading to the exact Outlook name is the approach that works for every path, and it makes a classic import easier to review too.

The validator suggests a destination from each header name only, never from cell values, and defaults unknown columns to Ignore. Ignored columns that still contain data produce a review, so nothing disappears silently. Two source columns cannot feed one Outlook field. If a file has two Email columns, the second is suggested as E-mail 2 Address and you confirm the choice.

Step 5

Save as comma-delimited CSV UTF-8

Microsoft's import article says that for best results the CSV file should use UTF-8 encoding, and warns that characters outside the English alphabet, such as Greek, Cyrillic, Arabic, or Japanese, can cause problems otherwise. If text does not display correctly during the import, Microsoft says to cancel, convert the file to UTF-8, and restart. In Excel, the documented save type is CSV UTF-8 (Comma delimited) (*.csv).

The delimiter matters too. Microsoft's classic Excel import article notes that some locales use semicolons by default and that Outlook does not accept semicolons as separators, so you may need to replace them with commas. The validator blocks semicolon- and tab-delimited sources and always writes comma-separated output.

Workbooks need one more step. Microsoft says Outlook can import CSV files but not workbooks with multiple sheets, so save the sheet you need as CSV; the original workbook is unaffected. The CSV article also warns that if Excel saves in its native format, Outlook cannot use the file. The validator reads one selected sheet locally, and its downloads are UTF-8 with a byte order mark, every value quoted, and LF line endings.

Step 6

Check emails, phones, and dates before Outlook sees them

Microsoft's import steps do not promise to reject a mistyped address, so catch errors before import. Every value in E-mail Address, E-mail 2 Address, and E-mail 3 Address should have a local part, an @ symbol, and a domain. The validator treats malformed addresses as blockers and reports only row and column numbers, never the address itself.

Phone fields should contain a phone number: digits with an optional leading +, spaces, dashes, periods, slashes, parentheses, or an extension. A note such as "call after five" belongs in Notes. This is a data-quality rule of the validator, not a documented Outlook rejection, but it prevents a phone field from holding the wrong kind of text.

Birthday and Anniversary need real dates. Microsoft's sample file writes them as month/day/year, for example 1/20/1981. The validator accepts that form or YYYY-MM-DD, blocks impossible dates such as 2/30/2025, and raises a review when a slash date is valid in both orders, such as 3/4/1990, because Microsoft does not document how an ambiguous date is read.

Step 7

Decide what should happen to duplicates

Classic Outlook asks the question for you. Microsoft lists three options: Replace duplicates with items imported, Allow duplicates to be created, and Do not import duplicate items, with Allow duplicates as the default. The classic Excel article describes replacing as replacing existing contacts, so choose it only when the file should win.

Microsoft's Outlook.com and new Outlook import steps say nothing about duplicates. Do not assume a browser import merges or skips anything. Check whether contacts already exist in the target before importing, and look at the result of the test import.

Microsoft does not document how Outlook decides that two contacts are duplicates, so the validator does not predict it. It blocks exact duplicate rows inside the file and flags an email address that repeats across rows as a review, because a repeat may be a duplicate, a shared mailbox, or two people at one address.

Step 8

Run the classic Outlook wizard carefully

In classic Outlook, choose File, Open & Export, Import/Export. Select Import from another program or file, then Comma Separated Values. Browse to the CSV, choose the duplicate option, and select Next.

In Select a destination folder, choose Contacts. Microsoft notes that with multiple accounts you should pick the Contacts folder under the email account the contacts belong to. Before Finish, use Map Custom Fields to confirm every column lands on the intended Outlook field, especially any column whose heading is not an exact Outlook name.

Select Finish. Microsoft says Outlook starts importing immediately and the Import Progress box closes when it is done. Then open the Contacts folder and check the result against your test plan.

Step 9

Import in Outlook.com or new Outlook

In Outlook.com, open People, choose Manage contacts and then Import contacts, select Browse, pick the CSV, select Open, and then Import. In new Outlook for Windows, open People (Microsoft says to add it from More apps if it is missing), choose Import contacts, then Browse, Open, and Import.

Confirm the signed-in account before you select Import, because there is no folder choice in these steps. If names or other text look wrong in the preview, follow Microsoft's advice: cancel, convert to UTF-8, and restart.

Step 10

Import a small test, inspect, then import the rest

Resolve every blocker, acknowledge the mapping and the mailbox plan, and download the first-25 test CSV. Import it, then open several contacts: names in the right fields, emails in the right slots, phones intact, dates on the intended day, categories, notes with commas or line breaks, and any non-English characters.

The normalized full download includes the same first rows as the test file. Before importing it, remove the test contacts or, in classic Outlook, choose a duplicate option knowingly; otherwise you may end up with two copies. If the test shows a problem, change the mapping or source rather than editing the output by hand, rebuild, and test again.

A completed import is not proof that every contact is right. Compare counts with the source, spot-check representative records, and keep the original export from Step 2 until you are satisfied.

Common questions
  • *

    Can I validate an Outlook contacts CSV before importing it?

    Yes. This local preflight maps each source column to an Outlook contact heading, checks headers, delimiters, UTF-8, emails, phones, and dates, and creates a small test file. It cannot see your mailbox or guarantee that Outlook accepts the import.

  • *

    Does the validator upload or save my contacts?

    No. Parsing, mapping, validation, masked evidence, and downloads stay in the current browser tab. Contact values are not sent to Microsoft or csvtodashboard.

  • *

    Can Outlook import an Excel workbook directly?

    Microsoft says Outlook can import comma separated value files but not workbooks with multiple sheets, so save the one sheet you need as CSV. The validator reads one selected sheet locally and writes CSV without uploading the workbook.

  • *

    What column headings does Outlook expect?

    Microsoft says Outlook requires column headings in the first row and that they must match Outlook's default language. Microsoft's sample contact CSV uses headings such as First Name, Last Name, E-mail Address, Mobile Phone, Birthday, and Categories.

  • *

    Why do accented or non-English names import incorrectly?

    Microsoft recommends UTF-8 encoding and warns that characters such as Greek, Cyrillic, Arabic, or Japanese can cause problems otherwise. Save as CSV UTF-8 (Comma delimited) and restart the import if the preview looks wrong.

  • *

    Will Outlook skip duplicate contacts?

    Only classic Outlook documents a choice: Replace duplicates with items imported, Allow duplicates to be created (the default), or Do not import duplicate items. Microsoft's Outlook.com and new Outlook steps do not describe duplicate handling, so inspect results.

  • *

    What date format should Birthday use?

    Microsoft's sample file writes dates as month/day/year, such as 1/20/1981. The validator accepts that or YYYY-MM-DD, blocks impossible dates, and asks you to confirm slash dates that are valid in either order.

  • *

    Does a ready verdict prove the import will work?

    No. A ready verdict means the file passes local checks and both acknowledgments. Mailbox choice, heading language, duplicate behavior, and the final result still need a test import and inspection.

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