TFL, transport for London can't sign in

If you scroll down their twitter account

https://twitter.com/TfL/with_replies

and look for a reply to @dskyward you’ll see they have security measures in place that prevents access from outside the UK.

If you need to contact them Twitter is probably best. Curious why you have a tfl account?

Thanks, ramblin' on. Most important: Does this mean my account will work again once I land at Heathrow? And will it work from my US cell phone?
Unfortunately (or not) I don't have a twitter account from which I understand I could send them a message. But I will try the Twitter website you furnished. I guess these security measures are pretty new at least within the last 6 months or so. I had no problem before that. The reason I have a tfl account is so that I can plan a journey and note favorites and places before I get to the UK. Since I have difficulty typing on a small phone it would make my life a lot easier if I could just click on 1 of my favorites rather than typing it in each time. But perhaps there is a way to do this without an account. Would you happen to know about that? I do know that I can no longer add places but my previously safe places are still intact

Just tried the website but it appears I would need to log on and since I don't have an account I can't do it. Still, the most important thing now is whether or not I can access my account from my US phone while in London. Again, my thanks

I'm in the UK and I just tried logging into the app. No problem accessing my Oyster account. Just wait until you get here.

By the way, I have a US phone.

Thanks, Frank. I didn't even know that this was an oyster account. I was just using tfl for transportation purposes! I'm glad to hear that you can log in with your US phone. Will definitely make my life easier, which I need as pre-share just canceled my flight from London to Marseille! Spent a bunch of money/miles and got a very long flight on KLM so it's still doable! Again, many thanks.

Have you tried using a VPN and changing your location to the UK? TFL may or may not recognise if you are using one, if they don't then there's a good chance that you'll be able to access the site as if you were in the UK.

Thanks JC,
But what is a VPN?

I've hit the same problem. I used to be able to log in from outside the UK, no longer can. And the messages is not very helpful, a security error. I would be better if they just put up a message "you can no longer log in from outside the UK".

A VPN is basically a secure connection to another computer, aka a "tunnel".
All your internet messages (both ways) go to the other computer, and then out to the internet, and vice versa. The website then just sees you as being wherever the VPN server is located, not where you actually are.
You would need a VPN server in the UK. There are some free ones. Google "free vpn uk ip address".

Also good to get at your Netflix account from a different country, they also block you if you aren't in the country in which you paid your subscription (copyright issues). And to get around internet bocks put up by governments (Turkey, China, US blocks on gambling websites etc.)

VPN is an acronym of Virtual Private Network. It's a system used to disguise the identity and location of the computer you're using. Basically you are pretending to be somewhere you're not. Most systems can be fooled but increasing numbers of online services such as Netflix, Amazon Prime, the BBC etc are putting systems in place that detect if you're using a VPN. The best ones are obviously the ones you pay for, there are free ones but typically they offer a limited version of their full software.