Yes, you definitely need estoppel certificates, and not just those the bank may provide, but make up your own as well. Use plain language asking them what they pay for rent, for CAM fees, what utilities are included, what deposit the owner is holding, what appliances or fixtures the tenants own and plan to take with them, what services they expect to be included, and any agreements they've made with the seller (such as seller promises to fix things, etc). I recently purchased a property with pretty bad leases. I asked all the tenants these things and one of them told me the seller had promised her a new window, another had been promised lights. I got the seller to pay for all these things. A year later, a tenant came to me and said that the seller had promised her $3,000 of improvements at her last lease renewal. It was in the lease, but had been renewed so long ago that I assumed the seller had already done it. I was able to tell her that because she had not mentioned it in the estoppel, even though I had clearly asked about landlord obligations, that the issue is now between her and the previous owner. You know, I always assumed that big commercial properties would be on a higher level than other investments, but they can be just as messed up as any other real estate investment! Good luck!