IN August Scottish Power will raise gas prices 19 per cent and electricity by 10 per cent – hitting 2.4 million customers.

They almost certainly won’t be alone. British Gas has already hinted it plans increases, and the Bank of England has said it expects an annual 15 per cent energy rise. It would be a major shock if all the other big six didn’t follow suit.

A fix guarantees your rate won’t rise for a set period and many on standard rates will save £150 a year if they fix.

It is possible to get online tariffs even cheaper, but these are subject to any rate rises, and even an 8 per cent rise (less than predicted) would mean a fix is cheaper in the long run.

This is all about speed. In the past, once price rises were announced, the cheapest fixes were soon pulled and replaced with more expensive ones and a switchover can take two months.

HOW DO I FIND MY CHEAPEST FIX?

On a Consumer Focus-approved comparison site and the ‘show only fixed tariffs’ tab – see the links at moneysavingexpert.com.

IS SCOTTISH POWER’S NEW PRICE ON COMPARISON SITES?

Yes, results are now based on the POST-rise prices. If you’re an existing Scottish Power customer calculate using kilowatt-hours used, not cost.

SHOULD I CALL MY EXISTING PROVIDER TO FIX?

No. Grabbing any fix could leave you locking in at a high cost.

Always do a comparison.

THE COMPARISON SHOWED ME IT’LL COST MORE TO FIX?

This is common if you’re already on a cheap discount tariff. Prices are predicted, though not guaranteed, to rise 10-20 per cent.

SHOULD I DITCH MY CURRENT FIX TO FIX AGAIN?

Past fixes are likely to be much cheaper than current ones (but check). If you’ve only a short time left, balance the cost of waiting when fixed prices may rise against the £50-£80 exit penalty.

HOW LONG SHOULD I FIX FOR?

Most fixes are 18 months, but longer ones at higher rates exist.

While prices are expected to rise long term, prices can drop over a shorter cycle.

I’VE A PREPAYMENT METER – CAN I GET A FIX?

No. Consider moving to a credit meter or switching providers.

TV money guru Martin Lewis runs the consumer revenge website MoneySavingExpert.com
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