She might be lying because she thinks if she told you the truth ,then you might say no and if you say no,then she cant go.My 17 continues to do this and it really bugs me.If he thinks i'm going to say no at all ,he will lie.we have had so many conversations(teary and angry ones) about this.i keep telling him that I cant build trust with someone who keeps lying.and I ask him "would you trust someone who lies to you?" and he says "no,of course not"...then he apoligizes and says he will stop,but it keeps happeneing.Not as much as he is getting older and more mature.i think it is pretty common and normal behavior but still can be dangerous and definitely does nothing to help trust between you two.Just talk to her about trust and when she lies be strong and have consequences.I have trouble with consequences,not my strong point at all but i know it works...xxxxx

the thing is i dont have a problem whos house she sleeps at , as long as i know where she is, at the moment she if grounded and not allowed to go anywhere

I have had this with my 14yr old and nothing I did worked. She would lie about everything from homework to going out.
All I have ever said to her was be honest no matter what you do, if there is trust then that's half the battle won, but she chooses not too and when there are consequences to her actions she runs away from home.
She has been told (by teachers) that basically she doesn't have to obey my house rules and that she can go live where she wants and at 16 I have no rights as a parent. So as you can imagine this has not gone down well in my house.
And yes my house rules aren't that bad, let me know where your going, text or call if your plans change. Be home by the agreed time (allowances are made) do the few jobs around the house to help out. etc.
I believe it's to push to see how far they can go and I have been told that it is normal. (sorry but I disagree with that).
she makes a big deal about hating people that lie, yet it's ok for her to do it which is quite frustrating.
Anyway sorry not much help all I will say is try to get to the bottom of it, maybe something is bothering her and she wants some attention, not able to approach you as she doesn't know how to say it she's going about it this way. Do you know any of her friends that may talk to you without causing a problem.
I do hope you figure this out and keep strong.

at the moment i have told her she is not allowed to sleep anywhere but home, i dont care if her friends sleep here but she must be home by dark. i have also told her that if i ring her mobile and she doesnt answer or text back straight away then she wont be allowed to go anywhere, its school holidays at the moment so really dont wont her home all day complaining, the couple of days she has been ok but we will see how she goes on the weekend

I have been blessed my son has learned from my example that lying is not OK, not even 1/2 truth but the last month he spent at an old neighbors home. She has a sneaky side to her so I am hoping he has not picked up bad habits...