We have two entities (LLCs) that want to open a checking account as tenants in common. Does anyone have experience with this or can you provide some feedback if this can be done? I'm trying to think through everything to see if this is even possible and if so what documentation would be required.

They each have the proper LLC paperwork for each entity.

It's called a "joint venture" and generally reflects a temporary arrangement; e.g. building a mall, between two legal entities. As you already have the documentation necessary to verify the existence of each, you need duplicate resolutions authorizing the same signatories from each entity; e.g. if they want to add or remove signatories, you need a resolution from each.

Neither is expected to die. "Tenancy in common" refers to their proportional ownership of the deposit.

Thanks Ken. We just haven't had this request before and I found out about it at 5:00 p.m. yesterday and the lender would like the account opening paperwork ready this morning when the customer comes in to close the loan. It would have been nice to have known earlier when the loan papers were in process.