Many people are outside the United States and must apply for their non-immigrant or immigrant visas at a US consular processing post. Others must take a trip home and apply to renew a non-immigrant visa before they can return. It is essential that these cases be submitted properly as there is no appeal if a case is denied by the consular officer. An experienced professional can spot issues that could be a problem if not addressed properly. People seeking visas may think an issue is irrelevant, but, in fact, it may present a problem. Past immigration issues could present challenges at a consular interview and it is essential all issues be explored prior to an application or interview.
In addition, some waivers of inadmissibility must be filed either at the consulate or at an address in the US specifically designated for those filings. In other cases, if the applicant is in the US, a waiver can be filed and decided before they leave the US.