--- title: "US port code 4581: Midamerican Airport, Illinois · Adhoc" description: "4581 is the US port of exit code for Midamerican Airport, Illinois on Canadian customs declarations." canonical: "https://www.adhocs.ca/us-ports-of-exit/4581" last_updated: 2026-07-27 --- # 4581 Midamerican Airport, Illinois US port of exit US port of exit · Airport 4581 is the US code for the port of Midamerican Airport, Illinois. A Canadian declaration uses it when goods left the United States through Midamerican Airport. - **Port code:** 4581 - **Port:** Midamerican Airport - **State:** [Illinois](https://www.adhocs.ca/us-ports-of-exit/illinois) - **CBP district:** St. Louis, MO - **Kind:** Airport ## Other US ports in Illinois - [3901](https://www.adhocs.ca/us-ports-of-exit/3901) Chicago (Port of entry) - [3902](https://www.adhocs.ca/us-ports-of-exit/3902) Peoria (Port of entry) - [3908](https://www.adhocs.ca/us-ports-of-exit/3908) Davenport, IA-Rock Island (Port of entry) - [3909](https://www.adhocs.ca/us-ports-of-exit/3909) Rockford Airport (Airport) - [3910](https://www.adhocs.ca/us-ports-of-exit/3910) Chicago Midway Int'l Airport (Airport) - [3971](https://www.adhocs.ca/us-ports-of-exit/3971) TNT Express Consignment, Chicago (Courier facility) - [3983](https://www.adhocs.ca/us-ports-of-exit/3983) Chicago Executive Airport (Airport) - [3987](https://www.adhocs.ca/us-ports-of-exit/3987) UFA UI Willard Airport, Savoy (Airport) ## Good to know - **Also a US port code.** 4581 is also the US port of exit code for Midamerican Airport, Illinois. Warehouse and US port codes go on different lines of a declaration. - **Which US port.** CBSA defines it as the US port where the truck or train crosses into Canada, or the one nearest to where it crosses. For goods sent by ship or plane, it is the US port where they were loaded. - **Courier shipments.** Low-value courier shipments name 1001, New York, as the US port of exit. Also in this directory: [CBSA offices](https://www.adhocs.ca/cbsa-offices) · [Warehouse codes](https://www.adhocs.ca/cbsa-warehouses) · [Border crossings](https://www.adhocs.ca/border-crossings) ## Questions ### What is US port code 4581? The code for the port of Midamerican Airport, Illinois. On a Canadian declaration, it says the goods left the United States through it. ## Sources - [Ports of entry](https://www.cbp.gov/contact/ports), U.S. Customs and Border Protection - [Memorandum D17-1-10, Coding of Customs Accounting Documents](https://www.cbsa-asfc.gc.ca/publications/dm-md/d17/d17-1-10-eng.html), Canada Border Services Agency Adhoc is not affiliated with CBSA or CBP.