Thinking of getting a credit card.

You can pay the credit card bill from anywhere, the bill will tell you what's involved.

In the case of a BoI Mastercard, the destination IBAN and BIC are at the top of the monthly bill with instructions to: 'quote credit card number as reference'. Every now and then, I pay my BoI CC bill from an EBS Money Manager account. Once you set it up as a payee, it's a piece of cake after that.

you can get €225 cash back a year on an Aib platinum card. I do all my day to day spending on the credit card, Never use my current account for anything, everything goes on the cc.

You can't make mortgage payments with credit cards.

Effectively that would be paying secured debt with unsecured debt, hence not permitted

Hold on, is it that easy? I'm thinking between a few flights and accomodations bookings annually, 5k would be easily reached. Any reason the cash back would be pulled?

Remember that you are not getting two free flights : you are getting two flights with no charge for the basic fare but will still have to pay all the usual taxes, airport charges, accessiblity levies, fuel surcharges, etc, etc. Chances are the fare element of any ticket is going to be less than 60-odd Euros, so you'll barely be breaking even.

As a rule, you should only consider signing up for any particular credit card on the basis of its reward scheme if the reward contributes to or enhances something you already do. Frequent flyer miles, for example, are far better used to upgrade a ticket you were already going to buy than to part-pay for flight you might well be able to get cheaper with another carrier.

I am not a big spender, but use a credit card because I my income comes in fits and starts. It means I can take advantage of special offers for big-ticket items that fall a few weeks before I'm due to get paid, knowing I'll be able to pay it off from those funds and don't need to dip into my savings.

So spend at least 5k per year. That's a family holiday or 2.

Is there any other catch if I only used it for these few big spends bar 30 stamp duty?

I have had the card for a few years and I am happy with it.

The flights I get with my CC perk are usually less than €30 but, that is hand baggage only, so factor in the cost of a checked in bag in addition.

The CC also comes with free annual travel insurance, if you have that anyway, it offsets the annual fees pretty much.

When you make your purchases you will get 1 Avios point per €4 spent and more on their e-store i.e. 8 points per euro on hotels or some shops - Tesco Clubcard points can be converted at 600 points per e2.50 of vouchers. You don't need a BOI CC for this perk, the points are in addition to those collected on your CC.

This year I booked Marrakech on Avios points for 8,500 points each including a 20kg checked in bag, cost was e68 - i.e. e34 each.

The points build up, in addition to the 2 free flights annually - it may take a couple of years but, its money you are spending anyhow.

If you have good discipline to clear your balance every month and put all day to day spending that you would typically put on a debit card through the CC and pay it off, the points build up and, if you work the e-store (if I, or the wife) want anything from M&S, look at it in-store then order online and collect 8 points per euro - yes, its extra work but like people into couponing, you get more benefit with a little work.

Currently BOI have an offer of introductory points to get you on the way.

OP does not want a CC per se but will take one on to get the free flight benefit of the Aer Credit card, if it is financially viable.

I've the BOI CC, used the free flights on flights that cost €480 cash and I paid ~€25.

Other than the €5k on the first month to activate the free flights haven't used it since.

I still need to use up the other flights at some point.

There's definitely value to be had with the free flights if you know what you're doing and can plan on advancr

A lot of fear mongering on here. I buy everything on my credit cards and have them set up on 100% direct debit each month. All the benefit no extra costs. Set and forget