GST Bill missed in Return

One month interest will have to be paid for full amount @ 18%

Even if the amount is set off from credit ledger but supply is of previous month then interest will be paid in full as per strict letter of law 

Read section 50 of cgst act

Proviso to section 50 is applicable only in the case where there is a delay in furnishing return u/s 39.Since in the given case GSTR 3B for December,2022 is already filed, interest shall be paid on the gross tax liability corresponding to supply missed to declare in December,2022

Totally on point CA Vidyasagar.

As per Section 50 of the CGST Act interest will become applicable at prescribed rate. In the initial stage of GST taxpayers was required to face litigation for payment of interest on Gross liability instead Net Liability. To reduce the ambiguity of the Section 50 of the CGST Act, proviso was inserted under sub section (1) which was notified with effect from 01-09-2020 so that to levy interest only on the net cash tax liability, except in proceedings under section 73 or 74. you can checked this NTF.( NT-01/2020-CT and NT-63/2020-CT)

Ok thanks for the reply . Understood .