What visa requirements do I need to meet as a 52-year-old Irish citizen visiting Thailand for a month?

You may want to look at this

My problem was with a particular immigration officer at Suwannabhumi Airport who wanted to invent reasons to deny my entry, simply because I had had so many (completely legal) long-term stays in her country. Among the things that she brought up was the lack of an onward ticket, which may or may not have been a valid issue for an American (me) who was entering on a passport and no visa (online advice on this matter was conflicting, and my return travel plans were uncertain anyway). Fortunately I managed to talk my way past her, and she finally backed off on the ongoing ticket issue, and the next officer she handed off to (who was the person who gave me the expected 45-day entry stamp) was a lot easier to talk with. So, given that experience, I STILL do not know what the actual rule is on the outbound ticket issue (!).

Anyone know if Thai airways ask for proof of onward flight on the direct flight from Heathrow to BKk?

Think you need a real passport (book).

As

@Bra****

said banked money is not an issue. As you have no prior history entering Thailand they’re not going to ask you to show cash.

The onward ticket is up to the airline. You’ll see a split difference of opinions on here. Some get away with no onward flight but many are asked - by their airline. If you don’t have one you may be denied boarding. You could ring and ask your airlines policy on that or Google “onward ticket” and get a throwaway one for around $10.

If you’re planning on staying over 45 days then you can either apply for an extension at a local immigration office (1,900 baht approx €50) for a further 30 days to get 75 days total or apply for a tourist visa and get 60 days on arrival (also extendable once so 90 days total) for £30 approx €35.

Money in the bank won't help you, since if they ask you to show proof of funds, it must be in cash only.

But they don't really ask for that unless they want to deny you entry.

If you have an Irish passport you don't need anything, just show up with your passport and you'll get stamped in for 45 days.

Your airline may require you to show onward travel within 30 or 45 days before they let you board your flight though.

45 day visa exemption on arrival . Onward ticket maybe needed by your airline