Hi chris and welcome to the forum
If you need to reduce your IVA payments, you will need to discuss this with the Supervisor and provide them with a current statement of your income and expenditure so they can advise whether it is viable for you to put forward a variation to the terms of your IVA. This is ultimately the creditors decision, and a further meeting of creditors would have to be called.
Discuss this important matter as soon as you can with the Supervisor.
Regards, Melanie Giles, Insolvency Practitioner for over 20 years.
For further details contact me at
http://www.melaniegiles.com and view my IVA blog at:
http://melaniegiles.blogs.iva.co.uk