Let's break this out into its own private function (put above other public functions):

```coffeescript
find_regex = (territory) ->
  for territory_code, regex of @postal_codes
    return regex if territory_code == territory
...
@regex_for_territory: (territory) ->
  regex = find_regex(territory)
  if regex? then new RegExp(result) else null
```

This way we can use a return statement and not have to set a variable/break. I'd also like to see some memoization of the regexes.