Starting in January 2019, if you are working as intermediary between owner and tenant in a holiday rental you have a new formal obligation with Hacienda: submitting “modelo 179”.
On March, 29th 2019 Brexit will be effective. If finally an agreement is not reached that includes a transition period, on the 30th of March UK will leave the EU market.
Including a non-deductible expense in your accounts can end up in an increment of the tax liability ( when it is removed) and a fine. Find here a list of expenses that you cannot include in your books.