Leader: Government sums don't add up

It seems the Home Office - the government department tasked with the now thankless job of promoting the case for the introduction of ID cards - isn't very good at numbers.

The week started off badly for the Home Office when parliamentary watchdog the National Audit Office (NAO) told MPs it was unable to sign off the department's accounts as correct because they were in such a mess.

A botched rollout of a new accounting IT system meant Home Office bean-counters, who handle an annual budget of £13bn, were unable to reconcile figures and, in just one example cited by the NAO, £3m simply disappeared without a trace.

This is the same department which has also been under the cosh for the last year or so defending its estimates for a £5.8bn price tag for introducing a national biometric ID card scheme, which critics claim will cost three times more.

Then today silicon.com revealed serious inaccuracies in the Home Office's bold claims, which were plastered all over the national media, that ID fraud costs the UK economy a whopping £1.7bn a year.

Scary stuff at first glance but there appears to be significant differences between what the Home Office classes as ID fraud and what everyone else classes as ID fraud. The Home Office, it turns out, lumps in crimes such as credit card theft and conmen trying to trick their way into pensioners' homes along with true identity theft.

Take out some of those more spurious figures and the actual cost of ID fraud comes in at less than a third of that figure, at just under £500m - still a big number, granted, but some way off the Home Office calculations.

The Home Office has denied that the ID fraud figures have been inflated to boost the case for justifying the extortionate cost of introducing national ID cards and even claimed that £1.7bn is a conservative estimate. But the Home Office also admitted getting that total is "not an exact science" and that there were "limitations" to the methodology used.

And this is why we should continue to question the Home Office figures and try to break the veil of secrecy surrounding the controversial ID cards plans. If this is how it does its sums, taxpayers should be very worried indeed.