Can you use a normal sim with our mobile broadband device?

There's a few potential hurdles...
The router might be locked to Vodafone and therefore only a Vodafone SIM will work. There is an unlimited VF PAYG phone plan for €20 BUT there is a possibility that the router might not allow a VF phone SIM in a Vodafone router. Only way to know is try it out.

You could also try another networks SIM to see if the router is locked, it might not be.

I use a "phone" Vodafone X plan/sim (with unlimited data) in a MIFI router in a remote location, €20 every 4 weeks. Been working for 2 years now without issue. Under the T&Cs, non-roaming data is actually unlimited (there's no hidden fair use limit like on a lot of other plans), but speed is capped at 10Mbps. Which is more than fine for my use. There's nothing in the T&Cs that limits what kind of device you can use it in.

As mentioned above, just make sure you're using the live.vodafone.com APN.

I used a three prepay SIM for over 12 months for all household internet usage, I used 1/2TB's some months due to vast amount of downloading and streaming. Never an issue with usage.

Package was '3 prepay 20', unlimited data.

SIM was inserted into a Huawei router.

Just went into threw shop and asked for a new SIM for my phone with new number. No questions asked!

Are you using the 48 SIM in the Alcatel R219T ?

I've had a 48 SIM in use in a router (Huawei at first, now a much better Asus) since January 2022 without issue, in case anyone is worried about being noticed/stopped. Not heavy constant use, but occasional heavy use.

This is what I'd like to do as i don't want contract right now and it's cheaper than broadband. I'm with eir on my PAYG phone and know the mobile data works well.

I've a few potentially silly questions here : If I go into the shop and ask for a new sim with new number do i have to register there and then and I'm presuming it's OK to have two different numbers with the same name. Someone might want to have two different phones.

Then is it a case that the sim itself is 5G or just all the latest Payg deals say 5G so I'd have to get a router for 5G? I'm a bit concerned if that'll work as my phone says 4G when I use the moblie data.

I'd possibly have to do something with that APN thing too. Ive been reading a lot about this. I checked 3 for coverage and it doesn't seem to be available even though I'm not that rural.

Alternatively, has anyone tried Eir's Mifi? I'd be stuck with a contract but sounds like a painless set up. Thank you.

@shmeee that's really helpful info, thank you very much. If I can avoid contracts I will! Hate them. Checked Comreg and ot says outdoor coverage for 4G for 3 is Fair. The 3 website itself says its working on 5G in the area so I get the impression maybe 4G is available but I'd be reluctant if the coverage is only Fair. I know for sure the Eir mobile data is fine here so think I'll stick to it. Good to know the 5G sim worked in the 4G router. This is all new to me but I was reading directions for what to do if the sim recognised it wasn't in a phone or something to that effect (or that's how I interpreted it). I think I'll give this a go. Might borrow a router to test it. Thanks a mill again for the info!

@A cup of te Try again. It can take an hour or two at times for the SIM to register on the network. I saw this when I got a portable hotspot + powered it on the first time. It took an hour or two to be able to access my data allowance.

Thanks both! I finally got a chance to try it again this morning and it just worked without doing anything. General Internet surfing is absolutely fine but I tested it for working from home and some of the functions for that are very slow to open but I think once opened they're OK. I'll know more when I test it again. I ended up getting a TP link archer mr200 ac1200 and a 3 payg just if anyone else is planning to use similar. Hoping the few early teething problems work out. If they do then I'm really happy with this set up :-) thank you for the advice previously also. I'm going to try the ethernet cable in it next time to see if that speeds it up.

A few months later now and it's actually been working great. No issues at all but I'll keep the above in mind in case I do run into issues in the future.