Tax Label Duplication

Tax Label Duplication

I have tax item called VAT14.5 which i used add manually at the time of item creation. 

Now I am importing items using the csv template. In the sheet I list tax name as VAT14.5. When I do this a new  duplicate tax label of VAT14.5 is getting created rather than using the existing VAT14.5 

So sometimes, an invoice has two VAT14.5 rows.

How do I resolve this?