Free accounts for limited companies

Dear all

I've recently begun to manage the accounts for a management company, managing the upkeep of a house, split into 5 flats.

Our current bank, Natwest has just informed me after 13 years of banking with them, somehow the account they opened on 2005 is not suitable for limited companies!

I am now trying to search for a suitable bank account for the management company, who:
- have an income of under £5K, to maintain the property
- essentially works as a not-for-profit

I can't seem to find any that fit our criteria or that don't charge a monthly fee?

Are there any accounts out there that are free in this situation?

Any help would be greatly appreciated.