The excitement for the new £5 note back in September amazed me; due it being brand new to the UK many people were selling the rare ones on for large sums of money when really you could probably only buy a quarter of your shopping or even less than that with it
However five months later the novelty of the new note has worn off with a lot of people and therefore we come to emotional part of the process where their are very few of the old paper five pound notes left. It is said that there at the start of the year there were still over 165 million paper five pound notes although by the end of spring they will not be legal tender anymore.
So what if you have a secret stash of the old £5 notes that no one knows about
Well I may just have the answers you are looking for.
The final cut of for using the £5 notes is May 5th 2017, so if you want to spend your secret stash on something worthwhile you have just under two months to go wild! It is said that some retailers may still accept the notes after the withdrawal date but this will be down to the discretion of the individual institution. If you do not spend your secret stash and are still left with the old notes the one place that will always accept the notes and swap them for the new notes is the Bank of England.
This may be a long distance to navigate yourselves too as the Bank is in London but this is the only place that will exchange your old notes for your new ones.
My advice: Spend your stash while you can 
