The Royal Mail looks after post code data files
The government is planning to give anyone free access to postcode data.
The move will be made as part of its commitment to make more use of technology and the web to transform official services.
Currently organisations that want access to datasets that tie postcodes to physical locations cannot do so without incurring a charge.
Following a brief consultation, the postcode information is set to be freed in April 2010.
The announcement about releasing postcode data came as part of a much wider plan to use technology as part of the Smarter Government strategy.
As part of this push, the government said it would start "consulting on making Ordnance Survey mapping and postcode datasets available for free reuse from April 2010."
A spokesman for the Ordnance Survey said the consultation would begin before Christmas 2009.
"It's a chance for anyone who has views on what can be given away to make those views known," he said.
"It's more a question of how not if," he said. "It's something that's going to be happening."
The dataset that is likely to be freed is that which ties postcodes to geographic locations. Many more commercial organisations use the Postcode Address File (PAF) that ties post codes to addresses. Currently access to either data set incurs a charge.
In October 2009 the Royal Mail took legal action that cut off the access many websites had to such data.
Sites that used the postcode feed included Job Centre Pro Plus, HealthWare (locates nearby pharmacies and hospitals), Planning alerts.com (monitors planning applications), Straight Choice (finds out who sent political leaflets).
Harry Metcalfe, who helped sites get at postcode data, said he was "cautiously optimistic" about the decision to open up the OS data sets.
"If the right data is released in the right way, this will be a positive development," he said.
Also included in the Smarter Government announced by Gordon Brown was the intention to get the "majority" of government services online in the next five years.
It also pledged a further £30m cash injection for UK Online Centres to help another million Britons get to grips with the web for the first time.