No, although it is a pity if they do not do so. The principal authority (usually the district council) conducts elections, and for the regular elections that come around every four years, poll cards are usually sent to every elector. The next periodic elections will be in 2015. It should be clear to electors what elections are taking place.
In the case of a by-election, the parish will have to pay the costs, and can choose whether to incur the additional cost of poll cards.
The ideal is that local councils should encourage democratic participation, seeking new candidates for council office and seeking the involvement of the electorate. That way, the council has a proper democratic legitimacy. Unfortunately, that does not always happen.