Anyway who still hasn't registered will not be able to vote on 6 May
There was a last-minute rush of people wishing to register to be able to vote in the general election, the Electoral Commission has said.
It said 50,000 registration forms were downloaded from its website on Tuesday, ahead of the 0000 BST deadline to get them to a person's local authority.
The Commission added more than 460,000 forms were downloaded from its website since 15 March.
Nearly half of these came after last week's prime ministerial TV debate.
Jenny Watson, chairwoman of the Electoral Commission, told the BBC's Today programme the debate did have "an impact".
"We did see a spike and we had a TV add running following the debate," she said.
"And it is an exciting election [overall], so of course you can't discard that."
Anyone who did not register to vote with their council by Tuesday evening will not be able to cast their ballot on 6 May.
Tuesday, 20 April was also the deadline for people wishing to apply for a postal vote.
To encourage more young people to register, the commission teamed up with social networking website Facebook to set up a "Democracy UK" page that linked to its About My Vote website.
The voter registration forms could then be downloaded from this site before being posted off to a person's local authority.
Ms Watson said about 14,000 registration forms were downloaded by Facebook users, and that just over 40% of all those visiting the About My Vote website were young people aged 18 to 25.
A spokeswoman for the commission said it was "delighted" by the response to its campaign to increase the number of people registered to vote.
"We're especially pleased that so many of the visits were from people aged under 25, who are one of the age groups least likely to be registered to vote," she said.
Ms Watson added that the commission was pleased that the deadline for voter registration had been moved much closer to polling day this time around, making this the first general election in which people could register to vote after the election had been called.
She said that because many people "don't get interested in a general election until the election is called", this had given a major boost to the numbers of people registering.
The Commission estimated a few weeks ago 3.5 million people had still failed to register to vote.
Although the deadline to register to be able to vote, or apply for a postal vote, has now passed, it is still not too late to apply for a proxy vote.
Voting by proxy means appointing someone you trust to vote on your behalf if you are unable to make it to a polling station in person.
Application forms for proxy voting are available online at the
About My Vote
They have to be printed out, filled in, signed, and returned to a person's local authority by 1700 BST on Tuesday, 27 April.
The person assigned to vote on your behalf will then be sent a special proxy poll card with details of where they should go to vote for you.
Although the general deadline for proxy vote applications is 27 April, if someone is suddenly incapacitated or taken ill, he or she can apply to vote by emergency proxy for medical reasons up until 5pm on polling day.