The UK government is in talks with banknote printer De La Rue to provide certificates showing that travellers aren’t carrying coronavirus.
The certificates would guarantee that UK travellers have taken tests for the deadly virus and are not infected.
The company today confirmed it is holding talks with the government and pharma companies. Also contained in the proposal are security seals and a system to check tests are genuine.
Unveiling its interim results today, company chief executive Clive Vacher said discussions were at an early stage.
He said: “We had conversations with governments and private companies about our authentication and security products that can be sold into that area very easily.
"They can track items through the supply chain from manufacture to point of use, ensuring vaccines are legitimate or people have been tested."
He said the company had the ability to produce billions of certificates.
“We have got great products that can authenticate vaccines and test kits, and provide immunity certificates,” he said. "It’s all at a very early stage so it's difficult to say if it’s going to turn into something or not.”
It is hoped that such certificates would help to ease international travel restrictions or help people return to work.
Qantas announced this week that passengers would need to be vaccinated to fly on its planes.
The concept of Covid passports does not have universal approval among scientists, however.
Janet Lord, professor of immune cell biology at the University of Birmingham, who sits on the Scientific Advisory Group for Emergencies (Sage), told The Times earlier this week that she was in favour.
“The current unknown is how long the immunity conferred by the vaccine lasts and thus whether follow-on boosters are required. This would determine how long the passport would be valid for as an indicator of immunity,” she said.
Ian Jones, professor of virology at the University of Reading, warned that an immunisation certificate was tantamount to making a vaccine compulsory.
Among supporters are former UK health secretary Jeremy Hunt and former prime minister Tony Blair's Institute for Global Change.
De La Rue reported a near seven-fold jump in first-half profit, buoyed by cost cuts under a turnaround plan, and said demand for cash has held up during the Covid-19 pandemic as central banks stock up.
The company, which lost the contract to make Britain's new blue post-Brexit passports at the end of September, said it was on track to save £23 million ($30.74m) from cost cuts in its fiscal year 2021.
De La Rue, which designed and manufactured the Bank of England's new polymer £20 note, has been focusing its efforts on delivering its turnaround plan, entailing cost reductions and investments in polymer notes and its authentication business.
In July, the company raised £100m in equity, dispelling material uncertainties that had clouded its future, and further bolstered its finances by extending a debt facility and temporarily reducing its pension contributions.
Mr Vacher said performance for the company's fiscal year 2021 had been positive and that outlook for revenue, profit and net debt for the year was in line with its expectations.
The company, which prints billions of banknotes a year, said adjusted operating profit came in at £15.3m for the six months ended September 28, compared with £2.2m a year earlier.
Its shares fell 7 per cent to 168p today.