The right to vote was exercised by the bailiff and burgesses (members of the town corporation, who need not necessarily be resident in the borough); this normally amounted to only 13 voters, though the report to Parliament before the Reform Act recorded the electorate as 42.
For most of Bewdley's existence as a borough until the Reform Act, the corporation (and therefore the choice of its MP) was under the influence of one or other prominent local families.