To cancel or not to cancel z visa? What are the consequences if a z type is not cancelled?

I am working in China and are here on a z type. The visa will run out in 4 months and I'm more or less done with my work here so will go back home within 1 month. The company that issued my visa still exists, but I have not been able to get in hold of any from the company who can issue documents to cancel my z type. Will it have any consequences for me if I leave without cancelling the visa? I will not be working on a z type in the near future but go to China for business trips