This event would occur if you do not have adequate balance in your bank account on the SIP debit date or the SIP Setup has not been approved yet. While missing a SIP instalment is not recommended and has its obvious disadvantages, it does not pose a serious issue transactionally. The payments will continue normally from the next month and there is no fine or penalty on the missed SIP. However, do note that some mutual fund houses stop your SIP if more than 3 months of the SIP instalments are missed.