You were not refused entry to the UK. The airline just refused to take you there, which is lucky because, if they had taken you to the UK, it seems that you would have been refused entry.

There is no need to mention your tale of woe if the application form specifically asks if you have been refused entry to any country. Refusal of entry has a specific meaning, and should be accompanied by a stamp in the passport. So if you are using the same passport and there is no refusal stamp, then you have nothing to fear.

You were simply not allowed to travel via the UK because you did not have the right type of visa to transit the UK. As is said above, you have not been refused entry to the UK or to Ireland by any immigration authority. You were merely refused permission to board the aircraft because you did not have the right documentation, just as you would be if you had the wrong ticket.

The simple fact is that you have previously been to Ireland for your interview, you did the right thing and left again, complying with your conditions of stay, and now you wish to return there to work and are going through the proper process to do so. That's what work interviews are for!

Full marks for wanting to be fully honest and open. If for some unlikely reason the issue of the earlier incident comes up, you should have nothing to fear. Even the most hard-bitten immigration officials know that travel agents are not always competent, and will see from your record that you had no reason to want to enter the UK illegally.

Don't mention it. PERIOD.

If you give them ANY ammunition, you only get yourself shot. As far as you are concerned, you were not refused entry into the UK or anywhere, it was airline staff that denied you boarding the flight, not any official!

Telling them you were denied entry to the flight is only going to make them look into it more and possibly find something else wrong to deny you on. In which case, you did it to yourself.

The way it stands: you were not denied entry into anywhere! No one can substantiate any different to that. And your knowledge only extends as far as customs officials permit.

My take: IF it EVER comes up, you plead ignorance on the basis you weren't denied entry to anywhere, stating as much and nothing more. I didn't think it bore any relevance since it had nothing to do with (INSERT AGENCY) I was travelling to Ireland, not the UK!!! AND I was only travelling for the purpose of an interview. I was only transiting through the UK, nothing more. That's it!

I would be inclined to mention it. If you choose not to and they find out then you will likely have a black mark. If you disclose it along with the circumstances (i.e. not your fault, just an error, not attempting to cheat etc), then they will take that into account and probably not even worry about it. In my (limited) experience with these types of authorities, they are generally looking for honesty and openness.

At the end of the day, it is hard to say exactly they will view any particular disclosure (or non-disclosure).

If you choose not to disclose, then you always have the option of saying that there was a mistake and when it was discovered, you voluntarily modified your travel plans so as to avoid any problems with "refusal of entry". So in your case, you are probably safe either way.