Upvote:5
The instructions stated at the time that you should post your application (post being British English meaning mail in American). The guidance has since been updated and now says mail instead of post to reduce this confusion.
Use the United States Postal Service, Priority Mail or Priority Mail Express services.
Upvote:5
Did you use a UPS envelope? The FAQ from VFS Global, the official processor for UKVI, explains how to do it as follows:
If you purchased Round-trip Courier, you will affix the Submission UPS Shipping Label to the front of a UPS envelope. Inside the UPS envelope, you will include the printed copy of Return UPS Shipping Label, along with a printout of your checklist (if you applied on AccessUK) or a printout of the front page of the application form (if you applied on Visa4UK), along with your supporting documents. Please make sure to check the address on the shipping label affixed on front of the package since applicants mistakenly affix the Return UPS Shipping Label to send applications to the UKVI. Make sure the “SHIP TO: “has the address of UK Visa and Immigration office in New York/Sheffield as per your application type.