I would say plug 'adult movie agency' or similar into google and see what comes up. I found plenty doing just that. I don't think there are any big companies in the UK that would just hire someone to be in a movie though, you'd most likely have to go down the same route as modelling where you build up a little portfolio, join an adult modelling site/agency, wait for casting calls etc etc...
Why the need for a title all in caps? I would give you advice, but I've already seen previous posts from you asking for repeated advice on how to get a bigger cock, so I won't bother this time.
Probably not a good industry to get into if you're insecure about yourself. You'll need to be fully body confident or it might make you feel worse about yourself.
Actually, considering you've asked a few times on how to increase size I think it's good you want to join that industry, it shows you've accepted yourself. That's a good thing. In terms of getting into that industry I'd try making your own and getting the, on websites, joining the chat line things on the tv, getting an agent. I don't think it's an easy thing to do though
I guess you could make a rule that if they ask for money, you assume it is a scam? Most of the modelling sites just want a few pics. They do casting calls for video shoots as well as photo shoots. I don't want to start linking but seriously, first page of google has legit ones.
You could always go down the arguably easier to get into route of cam work? You're not guaranteed much (or any) money but it's still performing to an adult audience and entirely based on the logic of making a little bit of money while having fun?
Have you thought about the future.... Like ten years from now when you want to settle down and have kids. I'm assuming thats a possibility because you'd at your straight on your profile. I don't know many women who would want an ex porn star as a husband and if you had kids how would you feel if they found out what you had done. Never mind your children in the future.... What about your parents now?!?! My parents would disown me if they found out. It's very easy in this day and age because everything is on the Internet It may all sound like fun and games now but you could live to regret it.
Have you thought about the future.... Like ten years from now when you want to settle down and have kids. I'm assuming thats a possibility because you'd at your straight on your profile.
I don't know many women who would want an ex porn star as a husband and if you had kids how would you feel if they found out what you had done.
Never mind your children in the future.... What about your parents now?!?! My parents would disown me if they found out. It's very easy in this day and age because everything is on the Internet
It may all sound like fun and games now but you could live to regret it.
i would never refuse to date someone if they were an ex porn star. and yeah you wouldnt show your kids the tapes but if my 13yo kid asked me why they watch me in a porn film id be more worried that they were looking at that stuff. if my 18yo kid questioned it, theyre adults, youre an adult its none of their business, nor is it your parent business. you make it sound like hes doing something dirty and sordid, people watch porn, people make porn, why is one worse than the other?
Totally agree with BV. If my husband was an ex-porn star I don't think we would be married! I just couldn't live with myself worrying that family/a friend/a work colleague would find out about it and see all of my husband's junk!
It doesn't matter how old your children are. I'm mid-twenties and if I stumbled across one of my parents in a porno I don't think I could ever look them in the eyes again!
The difference between watching porn and making porn is blindingly obvious, one you can do anonymously, the other is you being naked, having sex, for the whole world to see.
I wouldn't hold something like that against a potential partner, what they did before they met me was up to them! I wouldn't like my boyfriend now doing it though.
As for children, Tyger Drew-Honey is doing ok, so I wouldn't worry about that 
From a models point of view I don't think going the route of standard modelling agencies would help in anyway with this. I think a lot of them wouldn't take you on if you were an adult movie star.
I'm pretty sure there will be agencies focused on this line of work. It just takes some googling, maybe contact some adult film producers/companies etc. Is there a reason you're wanting to get into this sort of work?
Your saying uk mainland stuff that won't be distributed across the Internet.... Anyone can upload a photo on to the internet. The point of a photoshoot is photos for people to look at. Someone who looks at this may think wow look at this and lod it online. And then it's out there for ever!
I'd suggest staring your own site and using free ad sites to advertise. It's the way many people start off in the industry and personally from my experience, it's one of the better ways. When uploading content just make sure you check if the content is legel etc. You may see some sites with what you think is ok material and upload it and find there's issues with it as you have uploaded it within the UK (crazy I know).
Sex work open uni is worth looking into for further support and I'd recommend twitter.