The legal act of Voluntary departure allows an alien, who could otherwise be deported or removed, to leave the United States of America at their own cost within a specified period of time and thereby avert an order of deportation or removal.  That being said, in certain cases voluntary departure is not a viable legal option.

Voluntarily departing the United States of America is more desirable from an Immigration standpoint when compared to being forced to leave the USA pursuant to an order of deportation.  Should an immigrant (or non-immigrant) be subjected to an order of removal (deportation) he or she might be precluded from coming back the United States of America for as long as a decade and could be subject to criminal and civil sanctions if he or she reenters without first obtaining appropriate legal authorization.  Should the immigrant depart the United States voluntarily within the time frame ordered by the judge or offered by the Immigration officer, then he or she will not be estopped from legally reentry to the United states at some point in the future. It should be noted that a person who has a removal order on his or her record is not allowed to apply for removal cancellation, adjustment of status and/or any other United States immigration benefits for certain statutorily prescribed periods.

Cases involving voluntary departure often arise when a Thai is using an improper visa to try to enter the US. This is especially common for those who try to use a US tourist visa, but have obvious immigrant intent. For instance, Thai women who are going to the the United States on a US tourist visa to visit their fiancee could be turned away because the Immigration officer feels they should obtain a K1 visa for such a purpose.  Technically, Customs and Border Patrol (CBP) have the authority to put the prospective entrant through expedited deportation, but in some cases they will simply allow the visa holder to depart of their own volition.

In order to forestall the need for voluntary departure, to avoid the possibility of expedited deportation, and simply to be ethical, it is never wise to dishonestly apply for a US tourist visa, student visa, US business visa, or Exchange visitor visa when the applicant intends to travel to the USA for the purposes of marriage and adjustment of status.

(This is not to be used as competent advice on the law. No attorney-client relationship should be inferred from reading this piece.)