I found a couple of the old £10 notes the other day whilst cleaning out some drawers (the ones with Charles Dickens on the back). One shop refused to accept the note and told me to go to the bank to have it changed. I didn't mind at the time because I had the correct change but if I hadn't I would have probably stuck to my guns and insisted on seeing the manager.
Were they right to refuse the note? How long do you have before the notes no longer become legal tender and how long will the banks accept notes and coins for once new ones come into circulation?
On a related question, if I wanted to keep a cash holding for an indefinite period of time, what would be the best course of action? Considering UK banknotes change every few years, would it be best to keep the currency in dollars to avoid obsolence?