I am trying to create an inventory sheet -

Column A - Part Number (always the same) (ex. 10-0A in cell 2A)
Column B - Serial Number (needs to add 1 every new cell (ex. 0001 in cell B2
and needs to be 0002 in cell B3))
Column C - Invoice Description
Column D - Product Details

Is it possible to only add a new line when you start typing 10-0A in cell A3
and have the serial number column B add 1 to be 0002 in that column?

PART NUMBER SERIAL NUMBER INVOICE DESCRIPTION
10-0A 0001

If i click the cell below 10-0A and start typing is it possible to
automatically in the cell under the 0001 in the serial number column to add
+1 to make it 0002?

Thanks,