Idex number relating to name

I have a list of names in column A and I would like to create an index number based on these names.

Due to other information on the sheet each name is repeated several times but I would like to assign the same index number to the same name. So that for instance, if there are 500 records but only 130 names thre would only be 130 index numbers.

Hi,

1. First, use advanced filter to produce a unique values list

Select the range of names

Data > filter > advanced filter

Copy to another location

Unique records only


2. Then apply the index numbers to the list eg 1 -130 as you have suggested.

3. Use index and match (or vlookup) to match the names in the original list to the names in the filtered list with index numbers assigned.

Are the names listed sequentially ?

If not... let's insert some headers such that A1 & B1 are headers and names listed in A2 to A501 (assuming 500 records)... then

B2: 
=IF($A2="","",LOOKUP(10^10,CHOOSE({1,2},MAX($B$1:$B1)+1,VLOOKUP($A2,$A$1:$B1,2,0))))

Copy down to B500