The Home Computing Initiative (HCI), promoted by the Department of Trade and Industry and the Department for Education and Skills, takes advantage of a provision under the 1999 Finance Act.
Public and private-sector firms can capitalise on a pound;500 annual tax exemption on computer equipment worth up to pound;2,500. The exemption also covers peripherals such as printers.
The scheme was launched in 1999 but uptake has doubled since a relaunch in January.
The DfES already provides computers for schools under the Laptops for Teachers scheme, now in its third year and managed by the technology agency Becta.
Under the scheme, schools or local authorities are given computers, which staff can borrow on a long-term basis. More than 169,000 teachers have been given computers, but many thousands more are yet to benefit.
A Becta spokesman said: "The HCI scheme is not as straightforward as it seems and there are issues to explore, such as entering into agreements with a single supplier, but it is something for us to consider supporting."
Merchant Taylors' school in Northwood, Middlesex, has joined the scheme. Some 50 staff are about to take advantage of the initiative.
Andrew Goff, director of ICT development, said he welcomed the opportunity.
"Many staff need a second PC in their homes, and HCI gives them this with huge discounts," he said. "It helps the school by increasing the ICT skills of all teaching and non-teaching staff."
He estimated that a company could claw back as much as pound;9,000 on National Insurance payments if employees purchased around 50 average PCs.
For more information visit www.dti.org.ukhci or email Andrew Goff at Merchant Taylors' school: firstname.lastname@example.org