| Postcode | Country | County | Type | Status |
|---|---|---|---|---|
| England | Hertfordshire | Large | Terminated December 1996 | |
| England | Hertfordshire | Large | Terminated December 1995 | |
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | Terminated November 2021 | |
| England | Hertfordshire | Large | Terminated December 1984 | |
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small |