The following is an e-mail received from U.S. Customs:
From: MODISETTE, RALPH D [mailto:firstname.lastname@example.org]
Sent: Tuesday, February 02, 2010 6:29 PM
Subject: eAPIS Support
Hello Mr. Martin,
Once you have submitted a manifest through eAPIS, if you need to add additional travelers, you can submit another manifest with the same flight information. It is not necessary to resubmit the travelers that have already been transmitted, but you will need to resubmit the pilot each time as eAPIS always requires a pilot for each manifest.
For deleting travelers, once a manifest has been submitted, travelers cannot be deleted. It is not necessary to do anything further.
Changing of airports and/or times does not need to be completed in eAPIS as long as the flight is on the same date. For these changes, please contact the affected CBP airport. If there is a change to the date of a flight, a new manifest should be submitted through eAPIS.
eApis does not currently have the option available to cancel a manifest once it has been submitted. To ensure that a CBP officer does not respond to a cancelled flight, please contact the affected CBP airport to advise of the cancellation.
Specific CBP port information can be found at http://www.cbp.gov/xp/cgov/toolbox/contacts/ports/.
If you have any additional questions or concerns, please feel free to contact me.
Hope this helps,
Ralph D. Modisette
National APIS Account Manager
U.S. Customs & Border Protection
Office of Field Operations
By phone Mr.Modisette explained that a manifest filed for an afternoon flight from Freeport to West Palm Beach does not have to be changed if the flight occurs in the morning from Nassau to Tamiami, as long as the date, crew and passengers remain unchanged. All that is needed is for the Customs office of both destination airports to be advised (one that the flight is not coming and the other of the expected arrival time).
In a subsequent phone call he noted that the phone above is his direct line and unattended when he's not available, and that in his absence inquiries are best sent to email@example.com.
A screen shot of the actual e-mail, with the Customs logo as background, may be seen here.