London parents will receive only one offer of a secondary-school place as part of a sweeping reform of the capital's admissions system.
The reform is designed to create a "level playing field" for children by making it easier for parents to understand how to get the best deal.
The current system allows parents to receive offers from schools in many different boroughs even though this may leave other children without the offer of a place.
Critics complain that it favours middle-class parents who know how to work the system and ensures that disadvantaged children are left together in the least popular schools. A report by the Office for Standards in Education, published in October, called on councils and schools to share out problem pupils more fairly.
All 33 London boroughs together with eight surrounding authorities - Essex, Surrey, Hertfordshire, Buckinghamshire, Kent, Windsor and Maidenhead, Slough and Thurrock - have agreed the new system, which will be introduced from September.
Parents will no longer be allowed to hold on to a number of options for their child. Instead they will be given a single form on which to identify a maximum of six maintained schools in order of preference. Their child will be offered a place at the school highest on the list which accepts them.
All parents will then be notified by March 1, much earlier than at present.
A spokesman for the pan-London co-ordinated admission project said that the reform would end the annual scramble for places in June and July and reduce schools' bureaucratic burden.
He denied that the new system would encourage applications for school places further from children's homes. "Schools will still accept or reject an application according to their normal criteria. If a parent in Enfield applies for a place for their child in Richmond it is likely to be rejected," he said.
Dr Ian Birnbaum, Sutton's director of education and chair of the project, said: "Far fewer parents will be left with no offer and the system will reduce the anxiety many pupils and parents feel."
Figures published last term show that of the 1.03 million children in London's state schools, 138,500 attend classes in a different authority from that in which they live. In addition, more than 6,500 go to school outside the capital or attend private schools.
AGONY OF REJECTIONS
Eleven-year-old Harry Weskin started secondary this term, four months after his classmates.
Only after an autumn at home being taught by his parents, did he get a place at a school acceptable to his family.
Harry is just one victim of a London admissions system that every year leaves thousands frustrated.
Rejected by Forest Hill, Haberdashers' Aske's and Bacon's College, his parents decided they would keep him at home until a place became available at Pimlico school.
"I kept my son off school because the places offered were not what I wanted," Mandy Weskin, his mother, said. "I kept trying every month to see if the waiting list had gone down. I just pestered them."
She is angry about the whole experience . "It was a horrible a stressful time. I have a lot of friends who are going through the same thing at the moment and it is awful.
"I am glad they realise there is a problem but I wonder if this will solve it. There just are not enough good schools and some local authorities are diabolical," she said.