Increment a Value Based on Number of Values in an Un-ordered List in Excel

Question

I'll try to keep this as concise as I can, basically, we have a list of codes (AA, AB, AC, AD, etc) that need to have a number incremented based on how many identical codes are in the list, the trouble is that this list won't be ordered alphabetically, below is an example of what is needed:

AA     1
AA     2
AD     1
AC     1
AA     3
AD     2

I think my question is similar to this post and this article, but these solutions only seem to work if the codes are alphabetically ordered (AA,AA,AA,AC,AD,AD - etc)

If anyone could nudge me in the right direction I'd be grateful, I hope I have been clear enough, Excel has never been my forte so excuse me if the answer is actually painfully obvious.

Answer 1

B1=COUNTIF($A$1:A1,A1)

Data in column A do not need to be sorted.

Remember - the data can be visually the same but different (for example, it can have trailing spaces), in that case the formula will count full matches only.