Yes, it will be taken into account and count towards your length of membership with Nationwide.
For all ex-Dunfermline customers, your membership starts on 30 March 2009 as this was an acquisition rather than a merger.
How can I find out how long I've been a member of Nationwide for?
If you are registered for our Internet Bank or Banking app you can see how long you've been a member of Nationwide for. Or you can ask us in branch or ring us on 0800 30 20 11.