The construction industry’s new tax scheme is facing a crisis because the Inland Revenue is running out of vouchers.

A Revenue source admitted that it has only 200 000 CIS25 forms left, less than a week’s supply, and said contractors should use their remaining copies of the tax repayment form only in emergencies, where subcontractors were short of money.

Laing group tax manager Leslie Angell said: “We are desperately short; we have not got enough to work with. We live in hope that the supplies will come through before we switch to the new system on 5 November.”

In a letter to contractors, the Revenue said they should give priority to subcontractors that want to claim a tax repayment. The Revenue source said this meant firms should help companies that have just started up or need paying desperately.

The source said the next order of the specially watermarked paper used for the vouchers was not due to arrive until the end of this month. “Production takes a couple of weeks, so we won’t be able to fill any orders until mid-October. We haven’t taken action over stationery quickly enough.”

Subcontractors branded the mistake “shocking”. John Huxtable, chief executive of the Confederation of Construction Specialists, said: “This gives main contractors every reason to delay payments.” He added: “Some will be sensible and sympathetic, but those who want to take advantage will. After all, they don’t have to pay if the documentation is not legally in place.”

The crisis comes after the delay in the introduction of the Construction Industry Scheme. It was to have been brought in on 1 August to replace the SC60 tax scheme. But a three-month moratorium was agreed because many firms were not ready to make the switch.

In a further twist, the Revenue predicted that it would also run out of CIS24 vouchers soon.

However, the Revenue source said the industry must take part of the blame. “The industry has been slow in applying for cards and vouchers,” she said.

The new scheme is intended to stop money disappearing into the black economy by taxing more labour-only subcontractors at source.