I’m trying to create a formula in Column C to produce a running count of duplicate entries in column B.

As more account names are added to column B I’d like the running total of duplicates to add (+1) in Column C from the previous duplicate name in column A found. So every ttime a duplicate name is found column c would increase the count by one

Column B Column C
Intercontinental Marble & Granite Corp.
1
Pentagon Properties, LLC.
1
SAXX Mobile
1
Consulting RE, LLC Lake Placid Rail LLC
1
JC Corp
1
Steelcad Industrial Services
1
St. Charlest Properties
1
Xtra Airways
1
New Hawthorne Valley
1
New Hawthorne Valley
2
Consulting RE, LLC Lake Placid Rail LLC
2
New Hawthorne Valley
3

Thanks,