Excel Formula/VBA-Conditional Sum to find contra from multiple entries

Hi Experts,

I have a sheet which runs into over 30000 rows. I need to find contra entries within a company in column B for a each job in column C. Basically I need to find which transactions sum to 0 in column K (Balance in Base). so for example, in company code IN9073 in column B, there are 30 transactions which sum to 3,000 in column K (Balance in base). I have manually identified whether in each transaction is contra on not in column L (Marker2). If a particular transaction is not summing to 0, I have marked it as WIP.

The problem is there can be transaction with amount + and - which can be identified AND transactions where different amounts with different signs sum to 0.

I need this to be achieved by way of some formula or VBA. I tried sumifs but failed when there are 10 transactions out of which 8 are contra and 2 are not.

File is attached.

P.s. Rounding off to 1 or 2 is completely allowed

Thanks in advance.

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