Very limited roaming & I couldn't receive SMSs abroad
I picked this company for my PAYG SIM because its Penny Pro deal had the best pay-as-you-go prices I've seen, at 1p for 1MB / 1 SMS / 1 minute. I spend a lot of time abroad and only need to use my UK SIM every now and then to receive texts, so it seemed ideal for my needs.
However, be warned that Talk Home is not the best company if you need to use your phone outside of the EU, their coverage is very limited. I did not think it was a big deal because I was planning to use an eSIM with a different company for my data needs outside of the EU. But then I arrived in South Korea this week, and needed to receive a OTP code via SMS to log into one of my banks via multi-factor authentication. I turned on roaming and I had signal, but I could not receive any SMSs despite sending the OTP code multiple times, I tried calling my number from another number and that did not go through neither. I called Talk Home Support (from a friend's phone at extra cost, as I couldn't make/receive calls or texts from my Talk Home SIM), who informed me that Talk Home 'did not have any business partners in South Korea' and to manually search for a local network to connect to, which I tried but I could not connect to anyone. It was a big issue because I had an urgent need to log into my UK bank, and in the end I had to call my bank from abroad (from a friend's phone again) to be able to access my account. These calls were a hassle and cost me a lot of money that I had to repay to my friend.
So be aware, as cheap as they look, if you need to go outside of the EU, they could cost you more than more established telecoms providers.
