Ahoy!
There is a scheme where people start companies and get phones on the plans and sell them within the month (and not pay their carrier bills); the company is liable and the individual get off scot free with the proceeds from selling the phone.
I purchased a brand new iPhone 6s Plus sealed and checked the IMEI but at the time of purchase it was clear. A month later a block was issued on the phone that I did not know about until today - in my case 9 months later when switching carriers triggered the block.
You then need to go back to the carrier that blocked it (your provider can't help you). If you do not have proof of purchase they can’t do anything (much) for you. In my case although I did my due diligence, recorded the persons address, bank details to transfer and full name etc. still doesn’t change the fact that I would not have been able to do anything besides not buy these items on Gumtree unless I get a Tax Invoice.
If you need to check IMEI, this site is good and has some additional resources that may be of help.
http://www.lost.amta.org.au/IMEI
Just spreading the word, hope this helps someone make an informed decision going forward! ALWAYS get a proof of receipt from your buyer, never know when you may need it!
Mods, this is my first post so if posted to wrong place please redirect. Just trying to inform my Ozbargain family.
good info. hope you will get it sorted.