Okay, so first off, I apologize if this is a topic I have covered before, but it never seems to fail and it is an issue that comes up again, and again, and again... a new client will come in and they will hand over a stack of paperwork informing me they tried to evict a tenant, but the court would not allow them to do so. Now, I fully understand the motive to want to do something inexpensively and not having to pay an attorney, but as the saying goes, "he who represents himself in court, has a fool for a client." Well, this saying definitely holds true for those landlords out there trying to do their own evictions. Sure you want to save a few bucks and avoid having to pay an expensive attorney, so you think to yourself "how hard can this be?" After all, times are tough, and common sense would seem to apply: it's your property, the tenant has not paid rent or the lease is up and you want them out, so you should be able to just kick them out, right? Wrong.
There are some very strict rules when it comes to evictions in Washington State. The first rule is knowing that there are not "self-help" evictions in Washington. A "self-help" eviction does not mean that you cannot do it yourself (without an attorney), it simply means you cannot do an eviction without going through the court system (i.e. you cannot show up at the tenant's doorstep and demand they move out; nor can you do something like change the locks on a tenant and forcing them out of the house). These types of actions are unlawful and you can get into big trouble by doing something like this. So do not do it. You must go to court to properly evict someone.
Now, I realize this is going to seem like a ploy or a pitch to hire an attorney (or me), but the reality is, you do not want to mess up an unlawful detainer action by not knowing what you are doing. Failing to follow proper procedures can end up costing you more in the long run. If you do not give the proper notice, you will likely have to start over and give the notice again. If you do not properly file and serve the summons and complaint, you will likely have your case dismissed and in some circumstances the court could grant fees and costs to the tenant for your mistake (ouch!). Another way to think about it is this: in the instance where a tenant is not paying you rent, and you mess up the eviction process, then it simply comes down to lost time and rent from not having a new good tenant in your house who also pays rent.
So before considering doing your own eviction, talk to an attorney. In all likelihood an attorney can end up saving you quite a bit of money by avoiding mistakes and expediting the process.