I have been using Sage for the past 5 years for our business but literally only using the invoicing and recording payments features. I have never linked our bank up or anything and now we have gone VAT registered from May 1st.

I believe I need to set my bank up to be able to allocate transactions and also have tried to mark that we are now registered for VAT in my settings but it is saying I need to put in transactions from 2015 onwards which is going to be impossible to do. 

Has anyone had this experience before and if so please could you let me know where I should begin. Am I making it more complicated than it needs to be? (I really hope so) 

Sorry if any of what I have said sounds stupid but I am really out of my depth here a have never dealt with VAT within the business before.

Any advice of help would be much appreciated please.

Thanks.