| Postcode | Country | County | Type | Status |
|---|---|---|---|---|
| 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 | Large | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Large | Terminated May 1994 | |
| England | Hertfordshire | Large | Terminated July 2013 | |
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Large | Terminated December 1999 | |
| England | Hertfordshire | Small | Terminated June 2000 |