| Postcode | Country | County | Type | Status |
|---|---|---|---|---|
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Large | Terminated November 2000 | |
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Large | Terminated January 1995 | |
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Large | ||
| England | Hertfordshire | Large | Terminated March 2017 | |
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Large | Terminated December 2002 | |
| England | Hertfordshire | Large | Terminated March 2004 | |
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small |