| 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 | Large | Terminated January 1995 | |
| England | Hertfordshire | Large | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Large | Terminated December 2015 | |
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Large | Terminated June 1997 | |
| England | Hertfordshire | Large | ||
| England | Hertfordshire | Large | Terminated June 1999 | |
| England | Hertfordshire | Large | ||
| England | Hertfordshire | Large |