Is it illegal to share a room?

Going into second year we've found a 4 bed house. Me and my girlfriend want to share a room and split the rent while living with 3 others, is there anything illegal here?

It could be breaking your contract and cause problems if the landlord doesn't have a Hmo license so ask their permission first.

What's a HMO? What are the chances of being found?

Going into second year we've found a 4 bed house. Me and my girlfriend want to share a room and split the rent while living with 3 others, is there anything illegal here?

Looking at the contract it says no paying guests, what would constitute that?

That (in spirit) would mean not renting a room out on airbnb, though to the letter could mean that your arrangement wouldn't be allowed, only people occasionally staying over for free would be allowed.

I'd ask the landlord. Asking in person/by phone is more likely to get a yes (as it gives them a bit more 'flexibility' - it's up to them to report it, you wouldn't be doing anything wrong), but asking in writing, such as by email, is going to protect you more (as there's no potential issues of them claiming you breached the tenancy agreement).

Thanks for the advice. How accommodating are landlords often found to be do you know?

It'll depend on the person. Estate agents will probably be less accommodating than private landlords. That said, after a quick look at the guidelines on HMOs, any house with 3+ tenants has to be classified as one anyway, so the HMO issue shouldn't be any problem.

Providing that your girlfriend gets on the tenancy agreement, has the standard credit checks etc, and there are agreed processes in place for what will happen in the (hopefully unlikely) event that you two break up, I can't see that there'll be any problems with what you're suggesting (beyond the possibility of a small amount extra to cover utilities, as someone else alluded to).

You're a legend, thanks for giving some clarity to this. Will contact the relevant people!

Violating the terms of a contract is not quite "illegal".

There's a law against breach of contract. Technically, it's a civil wrong, but I had a post removed and got a warning here (for 'encouraging illegal [activities]') over a post on civil trespass the other day, which is only a civil tort.

Very illegal, im on the phone with the police this second

Thanks for the law lesson, bud.

Just one in response to your one and an aside to the rules of TSR.