There are two balance sheet forms, sch101 and sch100. Sch101 is needed when a corp. is filing its first ever return after incorporation. Sch101 is year start balance sheet. However, sch100 is always needed in each T2 return, it is year end balance sheet.
There is a basic rule for sch100 and sch101, they needs to be balanced:
Field 2599 must equal the sum of field 3499 and field 3620
Since Field 3640 equals the sum of field 3499 and 3620, so the above rule can also be written as:
Field 2599 must equal to field 3640