Kingfisher Gift Vouchers (KGV) has temporarily suspended trading following talks over the future of scheme-member Woolworths.
Woolworths shares were suspended on 26 November. KGV also runs Comet and B&Qs voucher schemes.
Employees who hold the vouchers under workplace motivation and reward schemes have been encouraged to redeem them while they can.
John Sylvester, executive director of motivation provider P&MM, said: “For the last two weeks we have been in contact with our customers encouraging them to spend their Kingfisher vouchers, which we believe the vast majority have done, enjoying some excellent bargains in the process. For those that have not been able to spend their vouchers we have put a process in place to ensure that, as far as possible, none of our customers loses out.”