My sim card won't work in my iPhone? I cut it to micro sim?

I've just cut my sim card into a micro sim, Placed it into my iPhone 4s and it states there no sim card in there, They phone was recently unlocked by Telstra and i know it's unlocked because i got a conformation message on iTunes.

I would have thought i cut it too small though that same sim card works in my Samsung Galaxy s2 Perfectly? What's the problem and why isn't it working with my iPhone?

If you cut it by urself then you prob messed it up and need to buy another one

You only need get your cutting lines slightly off and you make the SIM unusable. Some phones have a little more wiggle room in their SIM holder, and there will be a tiny bit of variance in every phone with regard to the SIM contact locations, so a marginally inaccurately cut SIM will work in some handsets and not others.

Try borrowing another microSIM, one which is not a DIY job. If that works you have your answer and must obtain a proper microSIM from your network operator and then get your number and any prepaid credit ported to your new mSIM.