VAT return query

After taking a look at the VAT returns my accountant made for me over the last 2 years, I noticed that he was missing my phone bill. The VAT I paid on the phone bill over a 2 year period equates to 450 euros. Am I allowed to increase my T2 figure by 450 in my next return? Or, is there a different procedure to handle such instances.

Thanks

Yes in so far as the phone related to your business. Say 70% business then claim €315.

Right so just to confirm. I make my VAT returns every 2 months. So when I complete my VAT returns for Nov/Dec, I can add the phone figure to my T2 for Nov/Dec, i.e. even though the phone figure represents a number accumulated over the last 2 years.

Should I include a explanation note with the return?

Finally, how far back does the revenue let you go with such corrections, 1/2/3 years?