As a penguin and therefore native of the southern hemisphere you may not have leave to remain in the uk. The plane is waiting to take you to the Falkland islands.
As a Penguin, you won't have to pay Income Tax or National Insurance but, being a chocolate biscuit, you'll have to pay VAT at 20%. However if you declare yourself to be a naturist Penguin, discarding the chocolate for a minimum of 6 months in any tax year, you can then live life tax free.