A school is to advertise a local estate agent in its newsletter to parents as part of a pound;500 per month sponsorship deal.
Martyn Gerrard estate agents will make the donations to St Mary's Church of England primary, Dollis Park, north London, in return for its company logo appearing on the monthly letter.
In a separate deal a local solictor has agreed to draw up wills in return for donations to the school.
Head Rob Allen approached the estate agents because his 480-pupil school must raise pound;26,000 in order to balance this year's budget. He said:
"The Government should be paying for the kind of education it says it wants. The idea of a school with McDonald's pencils or Marks and Spencer shirts in the school uniform is not somewhere I want to go, but I have had no choice."
Last July, when Mr Allen's budget deficit was pound;80,000 he and seven other Barnet heads lobbied the Government for more money to no avail. St Mary's budget deficit was pound;5,000 this year following pound;45,000 of cuts, which meant the school's toilets remained unrefurbished.
Warren Price, a director of Martyn Gerrard, which already sponsors the school's summer and Christmas fairs, has a daughter in Year 5. He said: "I was amazed to hear how underfunded they were."
Nigel George, of George and Co solicitors, Hertfordshire, is charging pound;195 for joint wills and pound;125 for single ones, which will be donated to the school.
Mr George, whose seven-year-old twin daughters India and Freya attend the school, will carry on the scheme for the rest of the year: "It struck me as a good idea because if you have children it makes a will really quite necessary. But it is terrible that schools have to find money by being sponsored by private businesses."
Carolyn Badham, a parent governor at the school, and her husband David had their wills drawn up by Mr George.
Mrs Badham, who has a daughter, Hannah, in Year 6, said: "The children were a bit spooked by it. But it had been on our minds for years and it was good to do it and achieve something worthwhile for the school."
One mother has agreed to abseil to raise money for the school, and another to skydive.
The Department for Education and Skills said school funding had increased in Barnet by nearly 7 per cent, the maximum possible. The national average is 6 per cent.
This meant that Barnet pupils got pound;3,488 a year compared to the national average of pound;3,110.
Since 1997 funding per pupil had risen an estimated pound;950 in Barnet compared with the pound;880 national average.