Yes. If your circumstances change or you receive a windfall, you may want to settle your IVA early. You can offer to pay off the IVA at any time during the term of the arrangement. The first step is to contact the Insolvency Practitioner acting as your Supervisor, they will need to put your offer to creditors even if you are offering to repay the original debts in full. Subject to the creditors accepting the offer, you will make the lump sum payment to the Insolvency Practitioner and shortly afterwards you will be discharged from the IVA.
Your creditors may accept an offer that is less than the total of your remaining contributions.