@fkraiem Your idea worked ! =) I created a French account on PayPal and I was able to add my credit card.

Makes sense (the fraud thing). Anyway thanks, I'll ask someone to pay for me (an Irish in Ireland or a French in France) ;)

For all the details, I've tried once with a french address on Origin. I had the same problem. At this stage, I though it could come from the fact that i'm on a student residence WiFi. So I tried to pay using my phone with 3G. I had the same problem. And only then I tried to register to Paypal and also had the same issue. That's why I'm asking now, because I don't really understand what is happening. ^^

Irish address on both.

You're right, Air France policy for over weight : "If the weight of one of your baggage items exceeds 23 kg, you must pay an additional fee of 70 €." (depending on the flight area)

I don't really know the weight of my lugage, I don't have any weighing machine, but I only have one lugage anyway. It's for a year so the checked lugage will be full of clothes and I'll have two computers on my carry-on.

Air France : 319€, Aer Lingus: 85.99€ and Ryan Air : 26.51€. The 9th of September (Date I'd like to go). I guess there are less or none chage for extra weight lugage with Air France, but it's basically a lot more expensive.

I'm not afraid of the ticket price, but more the lugage weight rules. I don't know how much costs and the weight of a checked lugage for Ryan Air. I've found this for Aer Lingus : aerlingus.com/travelinformation/baggageinformation/… But I guess it's a supplement with a "Plus" ticket (there is Low, Plus and Flex tickets). And I guess there isn't this problem using Air France, but it costs too much, I think I won't even try to look at it.