Britain's biggest privatization in decades captured the imagination of the public, with 700,000 individuals applying for seven times the number of Royal Mail shares on offer to private investors.
Despite the threat of strike action from delivery staff and criticism from the opposition Labour party, the government is close to completing the controversial disposal of a majority stake in the company, which is almost 500 years old.
Order books closed on Tuesday, with the sell-off expected to value the firm at around 3.3 billion pounds ($5.31 billion), the top of the government's target price range.
The flotation is one of Britain's most significant since the late 1980s and 90s, when British Gas and other state industries, such as the railways, were sold off.
Some 4.5 million people applied for shares in British Gas, which was privatized in 1986, raising 5.4 billion pounds.
"We haven't yet got the final figures but my very rough estimate is that we've had about 700,000 applications and it's about seven times oversubscribed,"
Business Secretary Vince Cable told a parliamentary committee, referring to the retail portion of the offer.
Financial bookmakers IG said the mid-price for shares in the grey market was 404 pence, suggesting investors could make around a 20 percent profit at the top of the government's 260-330 pence range when the shares begin trading on October 11.
The final details of the offering are due to be published on Friday, but the government has said around 30 percent of the shares on offer are expected to go to members of the public.
Individuals were required to spend a minimum of 750 pounds to invest, but the strong demand means orders are likely to be scaled back. Institutional investors have also been warned they should not expect to get all the shares they have bid for.
Cable said he expected the banks coordinating the sale to favor long-term investors such as pension funds at the expense of short-term speculators when allocating the institutional tranche of shares.