| Postcode | Country | County | Type | Status |
|---|---|---|---|---|
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Large | Terminated December 1983 | |
| England | Hertfordshire | Large | Terminated December 1981 | |
| England | Hertfordshire | Large | Terminated December 1996 | |
| England | Hertfordshire | Large | Terminated January 2005 | |
| England | Hertfordshire | Large | Terminated December 1994 | |
| England | Hertfordshire | Large | Terminated June 1997 | |
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Large | ||
| England | Hertfordshire | Large | Terminated July 2002 | |
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Large | ||
| England | Hertfordshire | Large | Terminated June 2017 | |
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | Terminated March 2008 | |
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small |