It is always difficult to predict what the creditors would accept and the offer should be as close to what they would be getting anyway as possible. Bear in mind that you are not 'tied in' to 72 repayments, as, come the time, you might be able to remortgage to release equity or raise a secured loan. If this is likely to be substantially more than the extra 12 payments creditors might decide to gamble and wait it out. That said a bird in the bush is always better ! It also depends on what sort of a hit the creditors are already taking - your payments are on the low side, so they will not be getting that much back in dividends.
I would go in with around £4.5 k .... but, as I often say ... I have seen low offers accepted as well as high ones refused (in one case actually higher than the projected return !).
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
Really appreciate the reply! My original debt was approx £15500. I can only find my proposal which states £2220 fee, 18% fees and 18p/£. This may have been amended slightly on the accepted proposal... which I cant find.
I understand with regards to the mortgage side of things, although I understand most people end up down the route of the extra 12 payments.