Hello @JamieSi_1704182 . It really depends how much data you normally use. You should be able to get an idea from the Usage History section of your dashboard.
Remember that, when EU Roaming, you can only use up to 12Gb in one month. If you need more, then you will need to purchase an EU Roaming Data pass for either 1 or 3 days.
You can see the prices in the Price Guide p16 - https://cdn.smarty.co.uk/files/SMARTY-Price-Guide.pdf
