| Postcode | Country | County | Type | Status |
|---|---|---|---|---|
| England | Hertfordshire | Small | Terminated May 1994 | |
| England | Hertfordshire | Large | Terminated December 1994 | |
| England | Hertfordshire | Large | Terminated December 1997 | |
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Large | Terminated July 2015 | |
| England | Hertfordshire | Large | Terminated December 1994 | |
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Large | Terminated October 2001 | |
| England | Hertfordshire | Large | ||
| England | Hertfordshire | Large | Terminated November 2005 | |
| England | Hertfordshire | Large | ||
| England | Hertfordshire | Small | Terminated March 2018 | |
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Large | Terminated March 2008 | |
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small |