How to mark the first occurrence of each value in Excel

Q: How do I keep only the first occurrence?

Filter the column for "First", or use =UNIQUE(A2:A10) for a list of distinct values.

Q: How do I number the occurrences?

Use the running count alone: =COUNTIF($A$2:A2,A2).

Formula (Excel and Google Sheets)

=IF(COUNTIF($A$2:A2,A2)=1,"First","Repeat")

Count from the top of the list down to the current row: =IF(COUNTIF($A$2:A2,A2)=1,"First","Repeat").

Result on the example: one result per row in B2, filled down to B10
Works in: Every current version
Google Sheets: Same formula

See it work

The formula is already in B2, filled down to B10. Change any input and the result updates, or edit the formula to experiment.

How it works

The range $A$2:A2 starts locked at the top and grows as you fill down, so each row counts only the rows above it plus itself. The first copy counts 1, later copies count 2 or more. Filter on "First" to keep one row per email.

=IF(COUNTIF($A$2:A2,A2)=1,"First","Repeat")

Result"First"

$A$2:A2"ana@northwind.example"
A range: one cell.
A2"ana@northwind.example"
The value in A2.
COUNTIF($A$2:A2,A2)1
COUNTIF: Counts cells that meet one condition.
- range$A$2:A2"ana@northwind.example"
- criteriaA2"ana@northwind.example"
COUNTIF($A$2:A2,A2)=1TRUE
The = operator tests whether the two sides are equal.
IF(COUNTIF($A$2:A2,A2)=1,"First","Repeat")"First"
IF: Returns one value if a test is true, another if false.
- logical_testCOUNTIF($A$2:A2,A2)=1TRUE
- value_if_true"First"
- value_if_false"Repeat"not used

In Google Sheets

The same formula works in Google Sheets: =IF(COUNTIF($A$2:A2,A2)=1,"First","Repeat"). We ran it in Google Sheets mode on the same data and it returns the same results.

Other ways to do it

Each one was run on the same example sheet.

Formula	Result	When to use it
=COUNTIF($A$2:A2,A2)	1, 1, 1…Different result	The running count itself: 1 for the first copy, 2 for the second, and so on. Shows the occurrence number.

Common mistakes

Lock only the start of the range. $A$2:$A$2 wouldn't grow, and A2:A2 would move entirely.
Sort first if "first" should mean the earliest date rather than the highest row.

Try it yourself

Same data, empty answer cell. Your formula is graded instantly, then re-checked on changed data, so a typed-in number won't pass.

Mark the first occurrence of each value

In B2, show "First" for the first time each email appears and "Repeat" for later copies. Fill down to B10.

Questions

How do I keep only the first occurrence?

Filter the column for "First", or use =UNIQUE(A2:A10) for a list of distinct values.

How do I number the occurrences?

Use the running count alone: =COUNTIF($A$2:A2,A2).

Checked by running on 2026-10-29: every formula and result on this page was calculated by the Spreadsheet Practice formula engine, in both Excel and Google Sheets modes.