Usually, yes. Especially for money that was deducted during the IVA.
If you think about it and the tax wasn't being taken, your income would have been higher and, therefore, your payment into the IVA would have included this anyway.
My opinions are merely that .. opinions based on experience. Always seek professional advice.
IVA Completed 23rd July 2013 .... C.C. 10th January 2014