Sending a summary to ACE and getting it accepted is very similar to sending it to ACS. However once you receive the response from ACE your processing will need to change.

Census changes
You are now required to send an electronic override message to CBP for any census warning. This override must include the reason that census warning was incorrect. Of course if the warning was a result of a classification or data entry error you just fix your problem and re-transmit. For more details see the Census Warnings section.
7501 not required
With ACE the 7501 form is no longer required for CBP purposes. For an ACE summary the transmission is the legal copy of your entry. So all accepted summaries are effectively paperless. However your clients will undoubtedly want a copy for their records. Additionally you may encounter import specialists that are unfamiliar with the change and will request a paper 7501. If this happens, you may want to draw their attention to the ACE Business rules document.
New notifications
ACE provides one or more entry summary notifications to let you know the status of your entry. These notifications may be issued even after the summary is accepted or paid. To help manage these notifications we have added a new option on the ABI View menu that allows you to view unanswered notifications. For more details see the Entry Summary Notifications section.
“Controlling party” matters
When working with ACE entry summaries, you need to remember that the “controlling party” matters. An entry is under trade control until it appears on a statement. Once the entry appears on a statement then the summary is in CBP control. As long as the entry is in trade control, you may modify, delete or change the payment date as needed. Once the entry is in CBP control, you’ll no longer be able to delete the entry. It may be removed from a daily statement and changed to a pay type 1 as long as RLF/AII is not in the picture.

When things break

ACE is still a relatively “new” system, and periodically has issues. But, if you’re having trouble - don’t despair. Here’s some things to try:

  1. If you’re getting a ACE system failure response when you send your transmit, just wait a bit and try it again. Customs periodically has trouble processing entries.
  2. If you’re having trouble with a specific type of entry or tariff combination, feel free to contact support or your ABI rep. There are some entries that need special adjustments to work on ACE.
  3. If all else fails, you can ask your ABI rep to deactivate the entry within ACE. That will allow you to resubmit the entry using ABI instead of ACE.