The core requirements
You were the victim of a qualifying criminal activity, you suffered substantial physical or mental abuse, you have information about it, and you have been or are likely to be helpful to the investigation or prosecution. Helpfulness does not require a trial, and it does not require a conviction.
The certification is the bottleneck
A certifying authority, which may be a law enforcement agency, prosecutor, judge, or certain other agencies, must sign a form confirming your helpfulness. Agencies are not required to sign, and internal policies vary widely. Requesting it early, in the right form, from the right person, is most of the practical work.
Expect a long wait, and plan around it
There is an annual cap on U visas and demand exceeds it. Waiting lists are long. Work authorisation may become available while a case is pending, which is why filing sooner matters even when the final decision is years out.
Family members
Certain relatives may be included as derivatives, and the categories are broader for younger petitioners. Whether a particular relative qualifies depends on your age and the relationship.
