You can let it fail by not making payments for 3 months - let your IP know what you are planning on doing. It will remain on your credit record for six years.
Is there any particular reason you can no longer afford it?
Sharing from experiences of dealing with debt
The greatness of a man is not in how much wealth he acquires, but in his integrity and his ability to affect those around him positively.
Bob Marley. http://kallis3.blogs.iva.co.uk
Why can you not manage these payments? Were your income and expenditure incorrectly calculated or is your spending out of check ?
If you cancel the IVA / allow it to fail, the creditors will add back lost interest and your overall debt could well be more than it was when you started. Have you got a plan for dealing with the debt now ?
My opinions are merely that .. opinions based on experience. Always seek professional advice.
IVA Completed 23rd July 2013 .... C.C. 10th January 2014 http://foggy.blogs.iva.co.uk