CAN YOU EVICT A COMMERCIAL TENANT WITHOUT GOING TO COURT?

It is not legal to change the locks on a commercial property without any notice or court authority to lock out the tenant for not complying with the terms of the lease - i.e. not paying rent.  There are certain procedures that a landlord is required to do, such as file an eviction notice and engage in the typical summary process legal requirements.  Indeed, if you are a tenant and have been locked out of your premises, you may have a cause of action against the landlord - i.e. a lockout complaint.  I suggest that you hire a lawyer to represent you in this matter as you should not be in the situation where the landlord has locked you out without him going through the judicial process.

No under New York State law you cannot employ the use of "self-help" which means just taking things into your own hands without court intervention. You not only may sued civilally for unlawful eviction, you may be held criminally liable for doing this. Even though it is a comemrcial lease and even if your lease provides for you to do this in case of a default, which most do, you must give the tenant notice. You have to give the tenant three days notice to pay the arrears and if no payment is made, you need to file a summary proceeding in the appropriate housing court. This also applies to a holdover situation wherein the issue is not money but a violation of another term of the lease. In this case you have to send the tenant a 30 days notice to leave the proemises before filing suit. Please do not use self-help

Eviction has to be done properly, using the court and legal process; what's called "self-help eviction" (e.g. changing locks; cutting off utilities; etc.) is illegal, and since it's illegal, could result in the landlord now facing liablility. Fortunately, the eviction process is fairly straightforward and inexpensive (at least if there's no real dispute as to the facts), so while it does take a little time and effort, there's no good reason not to comply with the law and use it. And note: if  you are going to court to evict a tenant, you can and should also sue them for any lease violations (e.g. unpaid rent or utilities the tenant was responsible for) or other losses or damages (such as damage to the premises) the landlord suffered.