The minimum payment is that agreed on the loan agreement and it is at the discretion of the loan company whether to accept reduced payments or not. If you pay less without agreement they can take whatever enforcement action they wish, up to and including bankruptcy.
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