The BBC have a program called ‘Pay off your mortgage in 2 years’. Tonight’s episode featured a couple from Cornwall with a mortgage of 90,000 GBP.

The program is moderately interesting for the various ideas people come up with to earn extra income (not for the scrimping, living off baked beans and giving up alcohol).

However, the program is spoiled by some very basic flaws.

Firstly, any extra income seems to be tax-free. If they did raise 45,000 GBP in one year, the Inland Revenue would demand a significant element. It’s a shame but it’s the law, you see.

The mentor repeatedly refers to his very clever ‘accumulator principle’ which involves simply multiplying a weekly income of ‘X’ by 104 to determine the additional income over two years. He (and the participants) seems to view this basic mathematics as some startling revelation.

Secondly, the mentor also dangles the thought of all the mortgage interest payments saved as an incentive to realise a livelong dream.

For example, he told tonight’s couple that if (surely when) they eventually do achieve their goal and pay off their mortgage of 90,000 GBP, this would free them from the shackles of 22 years of interest payments totalling 76,000 GBP.

The couple could then use this ‘money’ to buy a large, light, airy studio for painting and a home office.

The couple looked genuinely astounded and delighted. They did not have the basic common sense to understand that the very intelligent mentor had neglected to point out one important fact; to obtain this dream studio, they will either have to raise a further 76,000 GBP (which might take a while) or take out another mortgage.

Oh, the irony of it all.