The government says it doesn't know how many of its 12,600 suppliers are Manx companies.
A freedom of information request to the Treasury asked how many companies were listed as suppliers in the past 12 months.
In response, officials say 12,611 companies received some sort of payment from government departments over the last year.
But the government's financial accounting system doesn't record ownership information and so can't say how many of those are Manx-owned.