The taxes paid under the old Composition scheme can be carried forward as Input Tax Credits under GST. This would help you reduce your tax liabilities under GST.

How to claim tax credits:

• Credit should be taken on the basis of invoices or documents proving the payment of duty on excise or VAT. You should have those documents with you.
• Such invoices should be less than one-year old i.e., not older than June 30, 2016
• The stock of duty paid goods should be declared by 28th September, 2017 by filing form TRAN-1 on the GST portal

How can you claim tax credits from composition scheme:

• Make sure you are now registered under GST as regular taxpayer
• The input/goods with respect of which you want to claim tax credit should be used/intended to use for making further taxable supplies under GST
• You have all the invoices and other documentary evidence (for example, cash memo) in possession. And such documents should not be older than 12 months