| Postcode | Country | County | Type | Status |
|---|---|---|---|---|
| England | Hertfordshire | Large | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Large | ||
| England | Hertfordshire | Large | Terminated November 2001 | |
| England | Hertfordshire | Large | Terminated April 2012 | |
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Large | Terminated February 2021 | |
| England | Hertfordshire | Large | Terminated July 2001 | |
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Large | Terminated August 2001 | |
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Large | Terminated October 2005 | |
| England | Hertfordshire | Large | Terminated August 2015 | |
| England | Hertfordshire | Large | ||
| England | Hertfordshire | Small | ||
| England | Hertfordshire | Large | Terminated May 2005 | |
| England | Hertfordshire | Large | Terminated May 2011 | |
| England | Hertfordshire | Large |