One of the advantages for employees in a group health plan is the contribution most employers make toward the cost of the health coverage premium â in many cases, employers pay one-half or more of the monthly premium for an employee.
The basic format consists of five decimal numerical digits. An extended ZIP+4 code, introduced in 1983, includes the five digits of the ZIP code, a hyphen, and four additional digits that determine a more specific location within a given ZIP code. The USPS provides a free online lookup tool for ZIP codes.
As I've learned from my OWN mail, if the recipient has a post office box, the add-on code is usually the last four digits of that box number; if the box has only THREE digits, then the add-on code is 0 plus the box number.When did we start using zip codes? Area codes? In Britain it was in the 1980s. London has had postal codes since Victorian times.