Differential GST liability between outward supplies and return triggers electronic intimation, payment with interest, or explanation within seven days. Difference between tax payable in the outward supply statement and the return is dealt with through electronic intimation in FORM GST DRC-01B. The registered person must either pay the differential tax liability with interest through FORM GST DRC-03 or explain the difference within seven days. On receipt of the intimation, the person may make full or partial payment and record it in Part B of FORM GST DRC-01B, or furnish reasons for any unpaid portion. Unpaid amounts without an acceptable explanation become recoverable under the recovery provisions.