US Customs and Border Protection announced in CSMS# 19-000156 they would be deploying enhancements in ACE that will allow truck carriers to declare more than 5000 Section 321 shipments per manifest. They also announced they will be deploying a series of enhancements to improve performance and response time.  The notice also advises carriers will be able to submit more than 9999 shipments against a single manifest and instruction on how to submit more than 9999 shipments can be found by clicking on the CSMS message link above.