Car Tax

[Rod]

I purchased a new car end of last year and have just received an email from Albox council to pay the tax. When I open the PDF attached it has a bill on it and saying it is payable via the Virtual tax office. I did this and received a receipt for payment.
My query is that it had two amounts on the bill and two reference numbers. The top amount for 20 euros was paid but there is another amount underneath for 21 euros with a different reference number but when I put this number in it says it does not exist, anyone have any ideas what this is for to save a trip to the town hall?
Now just worked it out, the lower amount is for late payment as it has a different date on it.