Channel 4 has said it will not profit from phone lines on the eighth series of Big Brother, after controversy over its handling of a previous vote.
Davina McCall recently said she would host Big Brother "until I die"
It has halved the cost of taking part in the eviction process to 25p per call, with 15p spent on administration fees and the rest going to charity.
This will help to keep the process "fair and transparent", Channel 4 said.
It had to scrap a poll on Celebrity Big Brother in January after a mix-up in a vote involving housemate Shilpa Shetty.
An on-screen graphic invited viewers to dial in and "save" her while a voiceover gave the same number to "evict" her.
There was also controversy over the bullying of the Bollywood actress during that series.
And TV regulator Ofcom has ordered Channel 4 to begin the new run of Big Brother on Wednesday by broadcasting an apology for "serious errors of judgement" in its handling of the row.
However, police in Hertfordshire - where the show is filmed - have denied newspaper reports that they were to continually monitor this year's show in case of further incidents of racism or violence.
"Hertfordshire Constabulary is not setting up a team of officers to monitor events occurring in the Big Brother house," they said in a statement.
"Hertfordshire Constabulary will continue to police eviction nights as it has throughout the series.
"This is paid for by Channel 4 and Endemol, and not by public funds."
In a further change to the reality show's voting process, viewers will no longer be able to participate through text messages.
This is because of the lack of time during live broadcasts for mobile phone operators to count and verify the votes in the way that Channel 4 demands.
And all elements of voting will be monitored by an external law firm in future.
"The voting has been fair and transparent throughout Big Brother's eight years on air," said Andy Taylor, the managing director of new media at Channel 4.
This year's Big Brother house has been given a "topsy-turvy" design
"Given the recent focus on the use of premium-rate phone lines on TV, we want to ensure the audience has absolute confidence in the evictions, which are absolutely integral to the show's success."
This year has seen a number of controversies about the way that expensive voting systems are used by broadcasters.
Shows including ITV1's GMTV and The X Factor, Channel 4's Richard and Judy, and the BBC's Saturday Kitchen have been named and shamed over issues such as letting viewers enter contests which they had no chance of winning.
ITV recorded a 20% drop in income from premium-rate lines in March and April over previous months, for which it blamed a drop in consumer confidence.
And regulator Icstis has since introduced tougher rules for TV quiz shows, which broadcasters must follow.