correction in countif forumla

How do you get to the last 2 numbers? How are they worked out? Why is it 02 and not 01?

Your formula is checking if there is the value of A2 in the cell A2. Therefore it shall always be 01.

last two number is coming by order
meaning if i produce this product first time the number in B2 (16/02 will be 160201) but i produce it before for example will add 1 to previous number ( the number will be 160202 for the same product

the problem i think this formula must start from zero
as in my attached example in column F ( i add 160202 in F2 and the formula in F4 the same prouct not give correct number 160302 (correct number is 160303)

=IFERROR(LEFT(B2,2)&RIGHT(B2,2)&TEXT(COUNTIF($A$2:A2,A2-1),"00"),"")

That will start it from 0

not what i need
i want expain how this code
the code consist of number in B2 (16/02) first remove / 1602 and add number according to how many is produced before from the same product
160201 if first or 160202 if second or 160203 if third and soon 160211 if Eleven and soon

but can't become 160200 as your formula

Your formula is doing that fine with the letter in the first column or do you want the 160302 to be 160202?

No the value in B3 is 16/03 which will be 1603 this value not change with number of product produced , the change will occue only in last two digit according to number of the same product produced before

I don't see the issue then. What is wrong with the formula? You are counting the amount of Xs. Count something else if you want a different value. Can you please clarify what it is that is wrong......

=IFERROR(LEFT(B2,2)&RIGHT(B2,2)&TEXT(COUNTIF($B$2:B2,B2),"00"),"")

That is the only thing I can see that might be right.

please see attahced photo

That just shows as a red X. Can you please put in your spreadsheet how you would like it to look.

Try this in F3:

=IFERROR(LEFT(B3,2)&RIGHT(B3,2)
&TEXT(IF(COUNTIF($A$2:A3,A3)=1,COUNTIF($A$2:A3,A3),RIGHT(LOOKUP(2,1/($A$2:A2=A3),$F$2:F2),2)+1),"00"),"")

I try but its not working