Recommendations for actual SIM card (not e-sim) for Ireland.

I've used both GiffGaff and Three in Ireland. Both worked fine. I bought each sim on Ebay, they arrived reasonably quickly, activation was easy, and the prices were cheap.

GiffGaff: I bought the sim on Ebay in 2024 for $1.25 (with 5 pounds credit). It took 15 days to arrive (from France). I made an account and added $10 (Paypal or Credit Card). You probably want to use some of your credit to buy a "Goody Bag" as it's a better deal. I activated the sim on line just prior to leaving the US.

Three: I bought the sim on Ebay in 2024 from "The Roaming Company" for $7.44. Activated it through The Roaming Company. Adding cash to the account was kinda difficult if I recall.

Both sim cards worked in Ireland for me in 2024, and both "should" stay active indefinitely as they are both "Pay As You Go" accounts with no monthly charge. And they both worked back in the US (it was considered "roaming", so calls and text were pretty expensive). But after a few months, GiffGaff sent me texts that "roaming" had timed out from being out of the U.K. and the account would not be active.

I'll be back in the U.K. next month, though, and I expect to be able to use the Three sim when I arrive. But I don't know if the GiffGaff account will come back to life.

Oh yeah, both of these sims did not include a phone number. I don't need a U.K. number as my Tmobile account is still active there. But if you need to call others, you could use Whatsapp, Google Voice, or any other VOIP app.

Thanks.
I’m not going to the UK….just to Ireland.

(Can’t go to the UK for now, as with their new rules as of Feb 26th, I ( and millions of others world-wide) am now considered a UK citizen by descent….Canadian born to UK-born parents, and now need a UK pp to enter there. 🤦🏻‍♀️ )

Giff-gaff was great…I’ve used it twice, but as far as I know it always needs to be used for the first time in the UK itself, before using it in other countries, which is what I have always done.
Do you know if that has changed?
If so, I’ll order their card.
I’ll look it up.
Thanks.

it always needs to be used for the first time in the UK itself, before using it in other countries

I guess that is still true. I did activate GiffGaff online from the U.S., but shortly after, I flew to Ireland and it registered on GiffGaff towers, so all was good. When I returned to the U.S., it still worked, but was "roaming" at a high cost per call/text. But after a few months of "roaming", it stopped roaming in the U.S.