Run away, run away run far far away.
KaHn
/edit :- I realise this may not be helpful
+1
Run away, run away run far far away.
KaHn
/edit :- I realise this may not be helpful
My contract says nothing about kids, the previous tenants had a baby in the house
I'd look into it very carefully as you'll probably be much worse off financially than you already are. You gain an extra three or four mouths to feed and probably won't qualify for working tax credits at all unless your wage is a pittance.
Your council tax will instantly jump as you'll lose the 25% discount as a single occupier.
You will be entitled to childrens tax credits as a joint claim, but again the amount you receive is unlikely to bridge the financial drain of an extra three or four people in the house.
If she gets maintenance off her ex, remember you'll lose it as soon as you adopt the kids; in the event you then break up with her you'd become the one that the CSA go after, not the biological father.
Don't forget to factor in dinner money, fares, day trips, school uniforms (expect £300+ per year per kid if they end up in money-grabbing academy schools), regular clothes etc.
I'm not saying don't do it, I'm just offering a bit of cautionary advice.
Run away, run away run far far away.
KaHn
/edit :- I realise this may not be helpful
The kids are 2.5 years and 15 months.
Run away, run away run far far away.
KaHn
/edit :- I realise this may not be helpful

Yep taken on board, I'm raising the kids as my own anyway. Understand what you saying about the CSA. Adopting isn't something I would just do without thinking. Regarding council tax she is registered disabled so we should get some discount. The kids are 2.5 years and 15 months.
She must be good!
I did think you were making a mistake and then I noticed the ages of the kids... that means you've been with her less than 2 years?
Just have a quick look through your agreement but I doubt they will care too much unless they have had problems renting to families (ie kids wrecking the place). Unlikely but you never know.
It's a fairly standard term. If they split up and she stays, it can be a pain for the landlord. Having them as joint tenants makes it easier. It also means the landlord can chase him for monies owed in this scenario (disabled, on benefits = higher risk, not worth suing for court fees and lost rent).
Tell the agent and landlord, the agent will probably demand their excessive fees. If you don't, and they find out, then don't be surprised if you get a Section 21 through the door.