Does Degiro charge per order or per transaction?
An order is not a transaction.  It is a request to make a transaction.  If the transaction never occurs (e.g. because you cancel the order), then no fees should be charged. will I get the stamp duty back (the 0.5% tax I paid on the shares purchase) when I sell the shares? I'm not a UK tax expert, but accorging to this page is seems like you only pay stamp tax when you buy shares, and don't get it back when you sell (but may be responsible for capital gains taxes).  That makes sense, because there's always a buyer and a seller, so if you got the tax back when you sold, the tax would effectively be transferred from the buyer to the seller, and the government would never collect anything.