Electronic property searches using the National Land and Property Gazetteer (NLPG) generated successful matches in about 92% of cases, compared to 93% using the Postcode Address File (PAF), first introduced in the 1970s, for 600 randomly selected address searches.
The embarrassing findings emerged in a statistical report on the NLPG, a public-private partnership between Local Government Information House and supplier Intelligent Addressing. The NLPG is supposedly a trail-blazing e-government project.
The NLPG, which has been under development for three years, will underpin the National Land Information Service (NLIS) - an online search facility for land and property information essential for buying houses.
Address data experts seized on the report, undertaken by Intelligent Addressing and Local Government Information House, as proof that the NLPG has failed to deliver on its promises after three years and millions of pounds of investment.
"[The NLPG] has still to prove that it is any better than the existing address systems," said Robert Barr, senior lecturer in geographic information systems at Manchester University. "There is a danger that it may be considerably worse."
Earlier this year local authority IT professionals and suppliers claimed that up to 20% of the data in the NLPG may be inaccurate. The claim was strongly denied by Intelligent Addressing and Local Government Information House.
The NLPG's project leaders said a number of factors could explain why the address match rate for property searches using the NLPG database was lower than when using the PAF. It could be because the original enquiry format from the NLIS channels, which the report's searches were done through, was in the PAF format, they said.