Is savings interest 'additional income' for self assessment?

I just used the 'Do you have to fill in a SA' on the HMRC website but confused over one Q and A. If the answer to 'Do you get more than 2500 additional income?" is yes then you need to fill out a tax return. If my only additional income is interest on my savings in bank accounts, do I have to fill in a tax return?

Hi,
You need to register for Self-Assessment if your income from savings and investments is over £10,000 in the financial year.  
You can find further information here:  
Self Assessment tax returns Who must send a tax return