I'm sorry to hear of the problems affecting Nationwide Building Society's customers at the moment. According to the BBC, Nationwide is suffering from a system failure which is preventing access to online accounts.
Here are a few personal observations on IT Outsourcing based on my experience of both selling and working in and around major outsource contracts in the IT industry. My definition of outsourcing is, the transfer of significant IT functions and management to a third party. No matter how extensive, the use of third parties to simply augment internal resources is not, in my view, outsourcing.