Acknowledgment of service is a confirmation that someone has received a summons, writ, or other legal document they must respond to in some way, such as a notice that a person is being sued. People can simply sign to indicate that they received the document, but they can also respond in some way. There are a number of ways to serve legal documents, and the acknowledgment of service provides a method for confirming that the target did in fact receive the document and is aware of the contents, thus making it harder for people to legally challenge the service by claiming they never saw the document.
When someone files a lawsuit or a judge issues an order, personal service is the preferred method for delivering the legal declaration to the subject. This means that a person tracks down the subject and personally hands it to her, receiving an acknowledgment of service in return. If this is not possible, the document may be mailed or affixed to the last known residence of the target, or a process server may try to find another member of the household to accept delivery, such as the target's spouse or adult child. It is also possible to place a legal notice in a newspaper, but this is less useful because someone can claim to have never seen the notice.
The acknowledgment of service becomes part of the legal record of the case. It provides information about where, when, and how the document was delivered and is backup in the event that someone tries to contest the matter at hand. If a person fails to show up for a hearing, for instance, the acknowledgment of service is available to prove that the person knew when and where the hearing would occur, and had a legal obligation to show up or forfeit the case.
An acknowledgment of service in the form of a response could include something like a countersuit or a request to change the venue or time of a legal matter in the interests of making it possible for them to attend. People can also indicate that they received the document and do not plan to contend, allowing the case to move forward without them. People may do this for a variety of reasons.
If a person receives a legal document in error, as for example if a process server accidentally delivers a lawsuit to the wrong person, that person should make sure to address it, rather than assuming no further action needs to be taken. Before signing the acknowledgment of service, she can ask the process server for more information, and should contact the court to provide them with information about the mistake and make sure she is not legally liable.