Texas law severely restricts the circumstances under which your landlord may change your locks, remove your door, or otherwise exclude you from your own home. Your landlord is not allowed to use a lockout as a fast or easy alternative to a formal eviction lawsuit through a court process. And even when your landlord has legally changed your locks, they must give you your keys back upon request.   

Texas law provides tenants who are the victim of an illegal lock out with two remedies (both of which can be pursued):

First, Section 92.009 of the Texas Property Code allows the tenant to quickly secure a "writ of reentry" from the Justice of the Peace Court. The writ of reentry may be executed by the sheriff or constable using reasonable force.

Second, Section 92.0081 of the Texas Property Code provides that a tenant can file a lawsuit and recover compensation and penalties from the landlord as a result of the illegal cut off. Under Section 92.0081(f), the tenant can recover:

• One month's rent plus $1000;
• The tenant's actual damages (such a stolen property because of a removed door);
• The tenant's reasonable attorney fees;
• Court costs and interest. 

Money that the tenant owes the landlord is deducted from these sums. 

While the statute itself is poorly worded and convoluted, there are a few general rules that can help you determine whether a lockout is illegal:

A lockout is generally illegal if it's done in any way other than changing the locks. In other words, it's illegal under for your landlord to "lock you out" by removing your door, the windows, the hinges, etc. The only exception to this rule is for genuine repairs, construction, or emergencies.

A lockout is generally illegal if it's done for any reason other than unpaid rent or abandonment of the property. In other words, your landlord can't lock you out for making too much noise or failing to pay late fees. Again, genuine repairs, construction, or emergencies are an exception.

A lockout is generally illegal if it's done without adequate notice. The property code contains a number of strict requirements that a landlord must satisfy in order for their lockout to be legal. If the landlord fails to comply with those requirements - even by a little bit - the lockout is illegal and the landlord is subject to statutory penalties and the tenant's other remedies.

A lockout is generally illegal if the landlord won't give the tenant the new key, EVEN IF THE TENANT CAN'T PAY RENT. In other words, it's illegal for the landlord to lock out a tenant until they pay rent. The landlord has to give the tenant somewhere they can go or a number they can call 24 hours a day to get the new key. If a landlord won't give a tenant the new key, the lockout is illegal and the landlord is subject to the civil penalties above.