The new VAT conversion fraction is 1/6 (much easier to remember than the old one for 17.5%, which was 7/47).

If want to know the net cost of something, then divide by 6 and multiply by 5. For example, something sold for £100.00 has a net value of £83.33 (100/6*5).

If you want to know the gross cost of something, then divide the net value by 5 and multiply by 6. For example, a net value of £25.00 would cost £30.00 including VAT (25/5*6).

It may sound obvious, but changes to the rate of VAT affect the VAT amount, which in turn adjusts the gross value. £20.00 is not 20% of £120.00, it is 1/6 of £120.00.

VAT is an amount added by the supplier of most goods and services to what they sell, and which they must by law pay to the government. As individuals are usually not VAT registered, what we buy includes VAT, and is not reclaimable as it is to most businesses.

Offers by shops to cover the rise in VAT mean that they keep the sale price the same, but reduce the amount they get to keep after deducting the VAT they owe to the government. For example, if you buy a sofa before the increase for £500.00, the VAT due by the seller is £74.47; after the increase, the seller has to pay £83.33 to the government, meaning they are £8.87 worse off.

To most of us, the increase will mean very little, as the impact of adding 2.5% to the cost of a purchase is pretty small. For example, assuming no other changes to its price, an item costing £100.00 in the shop will be re-priced at £102.13. To incur, say, an extra £20.00 per month as a direct result of the extra VAT would mean you were spending £940 per month.

As an individual, it’s doubtful you will feel a financial impact from this change.

So although an increase from 17.5% to 20% sounds a lot, the only real winner will be the government. Some things never change.

So what should you be doing to make the most of the change?

Number one, now is the time to make large purchases, such as computers and other goods and services that have a high cost. The reduction on VAT should mean that they will cost you less. Don’t forget to haggle on price as well.

Number two, check your purchase invoices from suppliers. Make sure you are being charged at the lower rate of 15%.

Number three, check the sales invoices you are issuing. If you can justify making a supply at the old rate of 17.5%, then use it.

Number four, take proper advice if you are unsure what to do. Behind HMRC’s PR is an army of folk whose job it is to collect tax.

First off, the potential saving is 2.1%, not 2.5%. This is because the saving relates to the VAT, not the whole value.

So a widget that sold for £11.75 on 30 November should cost £11.50 on 1 December. The saving is therefore 25p. 25p as a percentage of £11.75 is 2.128% (call it 2.1%), not 2.5%.

Hardly something to write home about and I have my eyes peeled to find anyone who is actually passing this saving onto the customer. Anyone found a bargain yet?