No, you do not need a lawyer to file a civil complaint. In fact, the small claims types of courts might even have sample or actual forms for a plaintiff to complete and file. Even complex cases may be filed without a lawyer but the person risks making mistakes that could harm the claim. Having a lawyer might be helpful in the actual handling of the complaint prior to and going through trial. Courts might give forms but they will not give you advice on how to try the case. There are rules governing proper evidence that some people do not know about and when they get to trial they find that what they do have is inadmissible as evidence. A person with all inadmissible evidence has no proof and will lose the case even though the claim might be legitimate.