Cancer Research UK tested childcare vouchers on a pilot group of 12 staff in April 2005 after the tax and national insurance exemption on vouchers up to £50 a week was introduced. The tax-exempt limit has since been raised to £55 and the charity now offers the benefit to all of its 3,300 staff.

Currently, 90 opt for the perk, which represents a take-up rate of 2.8%.

Amanda Carrick, former reward and recognition specialist at the charity, believes the scheme is highly valued. "Staff realise that it probably doesn't come close to covering the true cost of childcare, but I think every little helps," she says.

The organisation has held roadshows with its provider Accor Services to help raise staff awareness. It has also distributed brochures explaining the childcare voucher scheme among other benefits.

Carrick says this level of communication has helped raise awareness of the benefits of salary sacrifice. "I think there was some misunderstanding of how salary sacrifice works, but they are getting there," she says.

She also believes that the scheme added little administrative burden for the reward team. "Cancer Research has an electronic voucher system, operated through a website, which is really straightforward," she adds.