Despite a looming deadline of less than five weeks, figures show that in some areas of Scotland less than 10% of people approved to sell alcohol have completed mandatory 'refresher' training.
In recent months, barely 7000 workers in outlets ranging from corner shops to hotels and nightclubs have completed training, with an estimated 18,000 still to attend approved courses by August 31.
Global drinks firms, lobbyists and lawyers have warned local pubs and corner shops are most at risk, with customers urged to remind landlords of the deadline.
Premises would have to close until they had a fully trained and approved manager, while those who have had licences withdrawn have no right of appeal and cannot re-apply for five years. Non-compliance also raises the prospect of prosecution.
Police Scotland previously said it would be proactive in ensuring licence holders are fully compliant.
The training is designed to weed out substandard operators in the trade and gave those with licences to sell liquor five years from autumn 2009 to update their training.
Mark Baird, head of alcohol in society for Diageo in the UK, said "There are real and pressing risks here, mainly for smaller pubs and off-trade retailers, the worst scenario, of course, being closure.
"We will be working with our customers to publicise and highlight the issue and perhaps customers of bars and off licences could also help by raising the matter with their local landlord or shopkeeper."
Figures from this month show of the 600 licence holders facing the deadline in the Stirling area only 50 have completed a course and notified the local authority.
In the Borders, the figure is 92 from 673 people; in West Dunbartonshire 45 from 390; Glasgow 500 from 2700; 147 from 920 in Argyll and Bute; and 234 from 1070 in North Lanarkshire.
Only Falkirk, has anywhere near half of its licence holders completing the training.
Leading lawyer Jack Cummins, who has advised the Scottish Government on licensing policy, said: "It's an alarming state of affairs for thousands of jobs and businesses.
"So far the Scottish Government has ignored calls for intervention. But the most recent figures suggest serious consideration may have to be given to emergency measures to defuse this ticking time bomb."
Archie Maciver, prominent lawyer and the Law Society's lead on licensing, said: "The authorities do not have any discretion to take a light touch. The Act is explicit. If the regulations are not complied with come D-day the licensing board 'must' revoke the licence."
The Scottish Grocers' Federation added: "Everyone with an interest in the licensed trade must give this top priority."
The Scottish Government said it had "undertaken a range of wide range of engagement activity with stakeholders, aimed at ensuring licensees are fully aware of their obligations".