A full swift code (or Full BIC code) is 11 characters long. The last 3 characters in the full BIC is optional as they denote the branch code ('XXX' is for primary office and should be preferred if you are unsure). If there are multiple swift codes mentioned for U.S. Bank NA, just use the first 8 characters. If even first 8 characters are numerous, then, use the one closest to your location or confirm with your branch office.