Brexit hasn't happened yet, so no issue there.
How much money are you talking about?
If it's a small amount gift it to someone you know who is travelling to the UK, or if you wlll be visiting Northern Ireland you can spend it there.
If it's a large amount take it to your local bank and get it exchanged.
I hope you haven't got much, and the old paper notes may not be changeable now.
As bryno says, brexit hasn't happened and has no relevance at all
I think the Brexit comment may be related to the drop in value of the GBP to other currencies.
Ah, could be. Having old 'paper' notes may be worse!!
£10 and £5 old style paper notes have already bene replaced, with £20 notes due to follow. If you have old style notes it will probably be very difficult to exchange them, if not impossible. Businesses will no longer accept them, and banks will only take them off their own customers.
Your only option may be to try the Bank of England in London. It might be possible that they can do something for you, but whethe rit wold be worth it depends on what and how much paper money you have.
i wouldnt bother exchanging it as the commission will barely give you like for like. i.e. 1£ will only get you 1€.
if it is a smallish amount, just put it in one of the boxes in the airport whereby it is donated to a worthwhile charity.
Good idea - the Charity box at the airport. They accept all currencies.
Aer Lingus will also send around a collection envelope during your flight that is dispersed to charities.