The duration of your stay in the United States is decided by the inspecting Customs and Border Patrol (CBP) Officer at the time of your entry into the U.S. based upon the time period necessary to carry out your business activities. You may be granted a duration of stay up to a period of one year ( 8 CFR § 214.2(b)(1)). The majority of approved visits are authorized for shorter periods, however.
The time authorized for your duration of stay will be indicated on the departure portion of Form I-94 Arrival-Departure Record, which is returned to you along with your stamped passport, after you have been authorized to enter the US by the inspecting CBP officer.
If you are required to stay in the United States beyond the period authorized on your Form I-94 to complete the business related tasks that were the purpose of your temporary visit, you may obtain an extension of stay. Extensions of stay can be granted in increments of up to six months ( 8 CFR § 214.2(b)(1)).
An exception exists for alien members of recognized religious denominations who are coming to the US for the sole purpose of missionary work. Such aliens may be granted extensions of stay in increments up to one year in length. Missionary work does not include selling articles or soliciting or accepting donations ( 8 CFR § 214.2(b)(1)).
You must depart the U.S. on or before the last day you are authorized to remain in the U.S. as specified on your Form I-94. Failure to do so will result in being out-of-status, which may cause you to be ineligible to receive a visa to enter the U.S. in the future.
If you wish to secure an extension of stay you will be required to submit Form I-539 Application to Extend/Change Nonimmigrant Status, along with the relevant supporting documents, to USCIS. You can find the instructions to Form I-539 here and the form itself here. USCIS suggests that you file Form I-539 at least 45 days before your duration of stay expires. The following should be submitted alongside your Form I-539:
Further, you must maintain a valid passport for the duration of your nonimmigrant stay in the U.S. If your required passport is not valid at the time you submit Form I-539, you will be required to submit a written explanation along with Form I-539.
Failure to complete all the information on Form I-539 or to send all of the necessary supporting documents may result in your request for extension being delayed or denied. As there is no appeal for denial of such an extension, it is very important that you provide all the necessary information.
Your Form I-539 can either be submitted via E-filing or filed by mail. If you choose to e-file, you will be required to mail all of your supporting documents to the appropriate receiving location indicated on your e-filing receipt. It is important to note the specific receiving location on your e-filing receipt for this specific reason, and to know to which address you should direct any other future communication.
If you are submitting Form I-539 and the supporting documents by mail, you will need to address them as follows:
For US Postal Service deliveries:
P.O. Box 660166
Dallas, TX 75266
For Express mail and commercial courier deliveries:
2501 S. State Highway 121 Business Ste 400
Lewisville, TX 75067
For more details information on B nonimmigrant visa status, please visit one of the following topics: