Refund of unutilized itc

Yes... Interest is applicable if it's utilized or not...

At what rate?

Interest rate @ 24%p.a.

Reason of reversal??

Yes interest @ 24% is applicable (Refer Section 50)

Unlike Service tax law, there is no difference in ITC CLAIMED and ITC UTILISED, so if u have claimed excess ITC then you will have to reverse ITC along with interest @ 24%. However, you may reverse ITC without any interest if the amount of interest is too huge and can then later defend to the authority.

Further clarification contact - CA SACHIN M JAIN | 8097515447 | casachinmjain @ gmail.com

No, there will not be charges any interest.
In case of M/S Commercial steel Engineering v/s state of bihar "Hon’ble Patna High Court held that ITC availed but not utilized for tax payment doesn’t invite penal consequences of Section 73 of CGST Act, 2017 and interest cannot be recovered on mere availment of ITC which was not utilized"

@ Archana Agarwal,

                                 section 50(3) provides interest @ 24 %, if excess/undue  ITC availed under section 42(10) or 43(10) which refers to ITC availed (mis-match) and utilized for payment of output tax liability only. Hence, ITC availed wrongly  but not utilized for payment of tax, then no provision under the GST Act levies interest thereon. 

If voluntary reversal then no interest.

If reversal due to some provision of the law then interest is dependent under which provision credits are being reversed. It can be 18%, 24% or no interest at all.