Clean a Candidate List for Your ATS

Candidate lists come from job boards, referrals and events, each in its own format. This example prepares a fictional list for import and shows why some repeated candidates should stay.

ℹ️ A worked example you can check. The before and after tables below were produced by the free tool on this site from a fictional sample file. Open the same file yourself and you will get the same result.

What Usually Goes Wrong

• One full-name column when the ATS wants first and last name
• Names in ALL CAPITALS from a job board export
• The same candidate applying for two different roles
• The same application exported twice
• Application dates in several formats

The Sample File, Before

7 rows of fictional data with the problems above. Every person and company is invented.

Open This File in the Workspace Download the CSV

Clean a Candidate List for Your ATS sample before cleaning
Candidate Name	Email	Phone	Applied On	Role	Source
ROSALIND HARGREAVES	rosalind.h@example.com	(303) 555-0131	3/16/2026	Data Analyst	Job board
emeka obi	emeka.obi@example.com	303.555.0132	3/17/2026	Data Analyst	Referral
Tavita Leota	tavita@leota-example.nz	+64 9 555 0133	2026-03-18	Operations Coordinator	Career fair
ROSALIND HARGREAVES	rosalind.h@example.com	(303) 555-0131	3/16/2026	Data Analyst	Job board
Rosalind Hargreaves	Rosalind.H@example.com	(303) 555-0131	3/21/2026	Senior Data Analyst	Job board
Anders de Vries	anders@devries-example.nl	+31 20 555 0135	22 March 2026	Operations Coordinator	Referral
Mei-Ling O'Connor	meiling.oconnor@example.com	303 555 0136	3/25/2026	Data Analyst	Job board

How to Clean It

1. Combine the sources into one CSV with the same columns and keep the originals.
2. Run it with duplicates, emails, phones, dates, name capitalization and Split full name.
3. Read the review list. The candidate who applied for two roles is listed as a pair that disagrees on Role and date.
4. Keep both of those rows if your ATS tracks applications; keep one if it tracks people.
5. Map first_name and last_name to the ATS fields and import.

Prefer the command line or an AI agent? The same result comes from smartdata-clean clean candidate-list.csv --dedupe-rows --lower-emails --merge-duplicate-emails --phones --dates --names --split-names. See tools for agents.

The Result

7 rows in, 1 removed, 6 out. The application that was exported twice is removed. Rosalind's second application, for a different role on a different date, is kept and flagged, because it is a different application and not a repeat. Names are split, including the two-part surname and the hyphenated first name.

Clean a Candidate List for Your ATS sample after cleaning
Candidate Name	first_name	last_name	Email	Phone	Applied On	Role	Source
Rosalind Hargreaves	Rosalind	Hargreaves	rosalind.h@example.com	+13035550131	2026-03-16	Data Analyst	Job board
Emeka Obi	Emeka	Obi	emeka.obi@example.com	+13035550132	2026-03-17	Data Analyst	Referral
Tavita Leota	Tavita	Leota	tavita@leota-example.nz	+6495550133	2026-03-18	Operations Coordinator	Career fair
Rosalind Hargreaves	Rosalind	Hargreaves	rosalind.h@example.com	+13035550131	2026-03-21	Senior Data Analyst	Job board
Anders de Vries	Anders	de Vries	anders@devries-example.nl	+31205550135	2026-03-22	Operations Coordinator	Referral
Mei-Ling O'Connor	Mei-Ling	O'Connor	meiling.oconnor@example.com	+13035550136	2026-03-25	Data Analyst	Job board

What the tool left for you

The tool listed these 3 items for a person to check:

• Row 6 shares an email with row 2 but has different Applied On, Role. Both rows were kept. Decide which is right.
• This list contains international numbers. 5 ten-digit number(s) with no country code were read as US/Canada (+1) (rows 2, 3, 5, 6, 8). Check that those rows are US or Canadian numbers.
• Name capitalization was applied to "Candidate Name". If that column holds company names or acronyms, check the changes in the log.

Checked, not just claimed

The original file, the cleaned file and the change log were run through the separate verifier. Result: PASS.

✓ Removed rows with a valid, verified reason: 1 of 1
✓ Rows: 7 in, 1 removed with a logged reason, 6 out
✓ Cells compared: 36; changed: 14; every change matched to the log: yes
✓ Log entries: 18; not matching the files: 0

The verifier confirms that the change log explains every difference between the two files. It does not judge whether each cleaning choice suits your situation; that part is yours.

The cleaning report

Report text for the sample file

SMARTDATAAI — CLEANING REPORT
Source: candidate-list.csv (fictional practice data)

SUMMARY
Rows in (excluding header): 7
Rows out: 6
Rows removed: 1
  Exact duplicates: 1
Cells changed: 17
  Emails normalized: 1
  Phones standardized to +E.164: 7
  Dates standardized to YYYY-MM-DD: 6
  Names re-cased: 3
Columns added: first_name, last_name

COLUMNS DETECTED
Email: Email
Phone: Phone
Date: Applied On
Name: Candidate Name

NEEDS REVIEW
- Row 6 shares an email with row 2 but has different Applied On, Role. Both rows were kept. Decide which is right.
- This list contains international numbers. 5 ten-digit number(s) with no country code were read as US/Canada (+1) (rows 2, 3, 5, 6, 8). Check that those rows are US or Canadian numbers.
- Name capitalization was applied to "Candidate Name". If that column holds company names or acronyms, check the changes in the log.

SAMPLE OF CHANGES (first 15 of 17)
Row 2 · Phone: "(303) 555-0131" → "+13035550131"  [phone]
Row 2 · Applied On: "3/16/2026" → "2026-03-16"  [date]
Row 2 · Candidate Name: "ROSALIND HARGREAVES" → "Rosalind Hargreaves"  [name case]
Row 3 · Phone: "303.555.0132" → "+13035550132"  [phone]
Row 3 · Applied On: "3/17/2026" → "2026-03-17"  [date]
Row 3 · Candidate Name: "emeka obi" → "Emeka Obi"  [name case]
Row 4 · Phone: "+64 9 555 0133" → "+6495550133"  [phone]
Row 5 · Phone: "(303) 555-0131" → "+13035550131"  [phone]
Row 5 · Applied On: "3/16/2026" → "2026-03-16"  [date]
Row 5 · Candidate Name: "ROSALIND HARGREAVES" → "Rosalind Hargreaves"  [name case]
Row 6 · Email: "Rosalind.H@example.com" → "rosalind.h@example.com"  [email]
Row 6 · Phone: "(303) 555-0131" → "+13035550131"  [phone]
Row 6 · Applied On: "3/21/2026" → "2026-03-21"  [date]
Row 7 · Phone: "+31 20 555 0135" → "+31205550135"  [phone]
Row 7 · Applied On: "22 March 2026" → "2026-03-22"  [date]

Values the tool cannot settle are left as they were and listed above. Where the day/month order of a date was worked out from other dates in the same column, that is listed above too.
Row numbers refer to the original file (header = row 1). Email checks cover format only; they do not confirm that a mailbox exists.

Where a Tool Stops and a Person Starts

Deciding person-level versus application-level records, matching roles to requisition IDs and fitting a specific ATS template are setup-specific. That is the CRM Import Prep service, which also covers ATS imports.

See Service Levels From $19 How We Check Our Work

Candidate data is personal data. Use the browser tools so the file stays on your computer, and follow your own retention rules.