Hi
If you have lost the sim card packaging...(your pin is listed on it)
You need to input a four diget pin to block the sim... yes that's correct!
You then will be asked for your PUK number to unblock...this can be found on your membership page (on my 48).
Enter PUK carefully - or you'll need a new sim!!!
At this point, you will have access to your phone.
See guide below:
http://community.48months.ie/t5/Most-Popular-Questions-Knowledge/I-forgot-my-PIN-What-now/ta-p/256🙂