Before I travelled to Europe in 2016, I did some research to find the best SIM card for phone use in Europe. You can read about it here “3” SIM Card
If you are in the UK, you can get them almost anywhere for 1 Pound. If you are outside the UK you can get them from eBay or online from simcorner
After 3 years, my thoughts haven’t changed. If you have a Vodafone Australia account, for $5 a day extra you can use your Vodafone sim card, but after 2-3 weeks even that starts to get expensive. The “3” pay as you go SIM is still the best deal in my opinion. The “all you can eat” pack has changed , the sweet spot seems to be the 12gig option for 20 pounds, and I travelled all over Europe in 2018 with that.
As the account doesn’t expire if you have a credit balance, I was able to use the same SIM card for a couple of years, so as soon as I landed in the UK, I popped it in my phone and was online straight away.
Now its 2019, I’m about to head off to the UK again, and unfortunatley it looked like I didn’t check or use the account enough and it had been shut down. I got a few years of trips from the one number, and now I’m heading off again in September, I’ve just purchased another one to replace it from SIM corner.
I’ve got a stop over in Thailand as well on that trip, so I’ve ordered one for Thailand as well to try that out. Unfortunately whilst the roaming on the “3” SIMs is great, it doesn’t extend to Thailand.