A lien search service is applicable when you search against a person rather than a property, trying to see any liens held against that person on all of their properties or responsibilities. You may be just looking for liens on a property without accounting for other factors, like judgements. A lien search can discover other properties; all liens cannot be found on a single property, since they are applicable to a person. For example, if there have been two owners on a property and both have liens against them, one may miss liens against the secondary owner.