Governing bodies of grant-maintained schools are required to have taken a preliminary decision on the new type of school they want to become.
The School Standards and Framework Act creates three breeds of school - community, foundation and voluntary.
The bulk of opted-out schools - around 900 - are expected to become foundation schools, the nearest to their present status.
County schools will be designated community schools while aided and former aided GM and voluntary-controlled schools will become voluntary schools.
To avoid distraction from the focus on standards, the Government has said that initially only GM schools will be able to seek to join a different category from that to which they are allocated. Other schools will be able to switch at a later date .
The only key dispute is the fate of GM church schools. Catholic bishops have already warned their GM schools that they risk being cut off from the Church if they do not return to diocesan control.
GIRL'S GRAMMAR: A LEAP INTO THE NEW FOUNDATION STATUS
TODAY almost 500 girls sit the entrance exam for the country's top performing state secondary. Both they and the 121-year-old school are taking a huge leap into the dark.
For Kendrick School in Reading, where last year 100 per cent of pupils gained grades A to C in their GCSE exams, is a grant-maintained grammar.
Fewer than one in five girls sitting their 11-plus today will be successful. Marsha Elms, its headteacher, is more confident about the school's future.
Kendrick has opted for foundation status but will have to work alongside a novice authority - Reading set up just eight months ago after the break-up of Berkshire County Council.
Kendrick went GM in September 1996. The move did not have the unanimous support of governors; staff were generally against it and Mrs Elms was philosophically opposed.
But she said: "With the break-up of Berkshire we really felt that becoming GM would give us a little bit more independence."
Governor Julian Le Patourel added: "We knew that moving from local authority control wasn't likely to bring us a crock of gold."
In the event, the school got Pounds 500,000 - Pounds 400,000 spent on health and safety work and Pounds 100,000 getting rid of dry rot.
But it saw the amount of money available for staff development increase more than three-fold and teachers who were initially worried that opting out would affect their jobs have been won over.
The abolition of the county council had a big impact on staff and Stephen Brown, head of IT, said: "The links with the advisory teachers went and in some respects that was far more significant than the act of going GM."
Financially the future of the school is far more uncertain than when it went GM. Staff costs account for more than 80 per cent of Kendrick's Pounds 1.8 million annual budget, leaving around Pounds 400,000 for everything else. In a good year it makes Pounds 30,000 on lettings.
The school has no savings and Mr Le Patourel said: "We need every Pounds 1,000 that can be negotiated out of the situation."
Kendrick has a good relationship with Labour-run Reading. Mrs Elms said:
"We might be naive but we trust the council."
There may also be safety in numbers - Reading has five GM and three local authority schools. And because it takes pupils from Berkshire and beyond, Kendrick believes its grammar school status is safe.
Despite its academic record, it appears to be far from an exam factory. Pupils are competitive, but they are relaxed.
Mrs Elms has overcome her "philosophical concerns" about GM and selection."I have seen the tremendous difference made to girls coming to a school like this. It would be morally unfair to take away something so good."
COMPREHENSIVE: BRACED FOR A RETURN TO THE LOCAL AUTHORITY
Situated in leafy Surrey by the banks of a canal, Fullbrook School is almost the stereotype of an affluent, successful grant-maintained school.
Signs of investment are everywhere. Approaching the school on foot, you pass signs advertising its new Pounds 3 million sports centre, complete with tennis courts and a gym. "We didn't go grant-maintained just for the extra money, " claims Graham Holliday, chair of governors. But both he and the head, Richard Elms, acknowledge they have received significantly more cash.
As well as the sports centre - which attracted Pounds 1m of lottery funding - the school is spending heavily on staff training -"probably twice as much as a local-authority school" - and computers.
Finance manager Doug Munson estimates the school has spent between Pounds 120,000 and Pounds 150,000 on computer equipment over the past three years.A local parent admitted that "nobody imagined it (going GM) would make such a difference."
The school is bracing itself for cuts when it returns to the education authority fold. Mr Elms joked that the cuts will be too appalling to contemplate and conceded that: "It will be quite difficult. Assuming Surrey gets a reasonable settlement, we hope we won't have to make any redundancies. "
Mr Munson attended a meeting recently where the local authority indicated about Pounds 15,000 a year would be available to Fullbrook for building repairs. "Last year we severely pruned back that category, we slashed it to Pounds 25,000. Previously we were spending Pounds 50,000."
Fullbrook opted out in 1994, after the local authority changed the secondary starting-age from 12 to 11. "There was a feeling that we had been ill-served with regard to the building work associated with that. There was wasted money, inappropriate building and little input for schools," explains Mr Elms.
Campaigning seems to have been low key. Brigid Saunders, a parent, was content to trust the board of governors. "I got the impression that if we didn't go GM we would miss out on funding. We never seemed to get what we needed."
But money was not the only reason to opt-out. Increased responsibility was a key attraction of GM status. "If something is successful it is down to us. If anything is unsuccessful it is also down to us."
So are they worried about losing control of their own affairs when they switch to foundation status? Mr Holliday seems relaxed: "Our autonomy should remain the same. Other schools are becoming more and more like GM schools."
Mr Elms agrees: "We feared that we might end up back in the Stone Age. There are many authorities who still hanker after that. But the authority has made a real effort to smooth the transition back. This is not the case with all of my colleagues elsewhere. There are some old scores still to be settled."