I'd be surprised if they accept that, they won't even let you change your address details via bank mail.
The banks logic on this one astounds me.I have used this method before. They cannot refuse to accept it.
Having done some work in banks on privacy matters I can tell you what their thinking is but in my view it just doesn't stack up. The logic is that they want to have people call up to change addresses (or make other critical changes) because of fraud issues etc. and they want the opportunity to confirm the identity of the person making the request. All good so far, but the implication of not accepting a request via bank mail is that that there must be an implication in there that they don't trust that the person making such a request is actually the owner of the account.
If this is the case though, aren't there a lot more security questions around internet signons and the security around these. If they really think their internet banking is not secure then I'm at a lose as to why they don't fix this problem, which seems quite a major one to me.