Policy & Resources (P&R) has hit back at claims that its new online tax calculator is “broken”, less than a week before deputies face off in a once-in-generation showdown over Guernsey’s financial future.
The online tool, which cost taxpayers at least £8,000, was launched to help islanders estimate how the proposed tax changes – including GST – would hit their pockets.
However, a detailed independent analysis has sparked an intense political row, with critics claiming the tool is riddled with gaps and mathematical errors.
But P&R has strongly defended the tool, flatly rubbishing claims that it was misleading.
Deputy Yvonne Burford, Vice President of P&R, said the committee had “never claimed the tax calculator guarantees absolute accuracy”.
Instead, it was designed to provide “a reasonable estimate of the immediate impact of the tax package for the majority of typical households based on the information the user supplies”, she said.
‘Sloppy and Broken’
The row erupted after software developer Jamie Collings decided to compare the tax calculator to the rules set out in P&R’s own policy letter – by building a piece of software to compare the two.
According to Mr Collings – who has over three decades of experience writing complex embedded software systems – P&R’s calculator gets the maths right for a single worker on a standard wage, but falls apart for more complex households.
Mr Collings claims the calculator:
- Omits an entire tax band: Completely leaves out a proposed 2.5% self-employed contribution band for high earners.
- Double-deducts mortgage interest: Mistakenly subtracts mortgage interest from the GST base twice and drops a statutory £3,500 cap.
- Ignores marital status: Automatically grants a personal allowance transfer to any two-adult household without checking if they are married or in a civil partnership.
- Offers only a “snapshot”: Fails to project future wage growth or general inflation, effectively ignoring how landlords might pass cascading GST costs down to renters.
Express has not independently verified Mr Collings’ technical analysis of the calculator.
He said whoever developed the calculator was “sloppy”, but he didn’t believe there was any deliberate political deception, because the tool under-reported some people’s potential savings while over-reporting others.
He told Express: “There’s no conspiracy, because conspiracy requires competence – they’re just idiots.”
‘They don’t understand their own policy’
However, he cast doubts on whether the civil servants who’d helped develop P&R’s new tax policy – or P&R themselves – understood their own numbers.
He told Express: “If they said [the figures the tax calculator gives are] correct, they don’t understand their own policy.”
Mr Collings explained that it was standard practice to test software before releasing it.
However, several major aspects of the tax policy appeared not to have been implemented in the tax calculator, he said, leading him to doubt whether the people testing understood P&R’s own policy.
He added: “To see that the self-employed band is missing, or that the marital condition has been dropped, a reviewer must first know that the band and the condition are part of the policy.
“The errors survived review because the policy was not understood by those doing the work.”
Snapshot criticism
Another criticism fired at the calculator is that it was misleading, because it presented household finances as completely static over time.
Deputy Rob Curgenven highlighted that the tool held income entirely at today’s levels and failed to factor in wage growth or general inflation.
“In other words, it answers one question and one question only: ‘What would life look like on day one?’” Deputy Curgenven wrote in a letter published by Express.
He added that it did not answer the question most people actually wanted resolved about what life would look like in five or ten years.
However, P&R said the tool was never designed to be a long-term forecast.
Deputy Burford also said P&R had “never claimed the tax calculator guarantees absolute accuracy”.
“It is accurate on the basis of providing a reasonable estimate of the immediate impact of the tax package for the majority of typical households based on the information the user supplies,” she said.
She added that there was a “significant disclaimer published alongside the calculator”.
Defending its static nature, she asked “how could it possibly predict the future financial circumstances of the individual?”.
“It’s a simple model that gives a good idea of the immediate impact for most people,” Deputy Burford concluded.
She said it “doesn’t, and couldn’t, cover every possible combination of circumstances”.
“However, it should be able to accommodate the impact on someone who has retired early from the workplace and is living on a private pension,” Deputy Burford added.
Deputy Burford clarified that benefits like the Essential Costs Relief Payment would not be one-off, but would be “available on an ongoing basis year-on-year”.
Inaccurate ‘stamps’ claim
Another criticism came from a local resident who claimed to have uncovered a separate, “massive flaw” affecting long-term workers.
The poster argued that the tool mistakenly calculates automated social security savings for early retirees who have already paid their maximum 45 years of “stamps” and no longer owe contributions.
However, P&R flatly rejected the social media claim, branding the allegation “inaccurate”.
Deputy Burford said the ability for an individual to stop paying contributions at age 60 after reaching a maximum history was actually repealed two decades ago in 2006.
Under current law, early retirees do still pay an 11.8% contribution rate on relevant income, meaning the tool’s projected drop to 8.5% under the new package is legally correct.
Battle over transparency
The calculator row has reignited a much deeper battle over government transparency.
P&R continues to reject demands from deputies to release data used to model the tax proposals including GST.
Deputy Burford told Express: “‘As we have already said, we cannot publish the model that calculates the aggregate numbers, because it contains very detailed and extensive individual and household data which is protected by Census and Income tax legislation.”
However, this is an argument that has been repeatedly rejected by opponents, with several deputies saying the claim the data was too sensitive to share didn’t “hold water”.
Mr Collings said he “didn’t care” about GST itself – or the other proposed tax reforms – but was deeply concerned about the “absolute lack of transparency”.
He argued that a major transparency problem remained, warning: “If they have confidence in that model and its data, there can be no impediment whatsoever to release it, but they never will, because they’re scared s***less.”
He argued there was a pattern of secrecy within the States, with “obfuscation, manipulation, redaction, evasion of freedom of information requests – it’s absolutely horrific.”
‘Idiotic’ spreadsheet
Mr Collings also questioned why the civil service relied on a massive 66,000-row Excel spreadsheet rather than high-level data to model the effects of the tax proposals.
Calling into question the civil service’s competence again, he said reports from deputies that the spreadsheet took more than half an hour to process a single change were “inexplicable”.
He said a well-constructed spreadsheet of that size should be able to run changes in “milliseconds – a few seconds at most”, adding that “it would only be that slow to calculate if you’re an idiot”.
He also questioned why the spreadsheet had 66,000 rows, when it was created using data from a 2019 household expenditure survey.
Mr Collings explained: “There aren’t 66,000 households on this island. There aren’t even 66,000 people on this island.”
“My suspicion is that actually they’ve got two sets of data in there.”
