Households facing 100% increases to their car insurance premiums and 25%-plus rises to home insurance renewals may well be able to slash the price by shopping around and using a couple of other tricks.

How do I know this? I’ve just done it – several times.

In the past few months the wider Brignall family has been on the wrong end of some big insurance rises, and in each case I have managed to avoid the increase by switching insurers – in one case saving more than £500 a year.

Last week the latest renewal notice arrived at chez Brignall: an email from M&S Insurance announcing that the cost of our home and contents cover was poised to increase at the beginning of August.

The cost to cover our distinctly unexciting 1980s Hertfordshire home was to rise from £324 to £407 – a hefty and, in my view, somewhat unjustified 25% increase. We have never claimed, let alone this year, and have bog-standard contents and rebuild cover. We do insure two sub-£1,000 bikes outside the home.

For years, insurers have offered an attractive cheap price in the first year, only to increase the price in the second. In 2021 the regulator, the Financial Conduct Authority, banned insurers from charging existing customers more at renewal than they would expect to pay if they were taking out a new policy – part of the loyalty penalty crackdown.

For a while, it seemed, the savings offered to switching customers like me all but dried up. However, three years on, it’s almost as if the FCA had never acted, and savings are very much available to those willing to move companies.

So how do you do it? Personal finance journalists are often extolling the virtues of price comparison websites, and I have tried them all over the years.

Right now, I favour Go.Compare – in part because it is easy to use, but mainly because it is (at the time of writing) offering free excess cover for users who go on to buy a car or home insurance policy via the site. This means that if you need to claim on the policy, it will pay up to £250 towards your excess.

This in effect allows users to opt to take a voluntary excess on their car or home insurance, knowing that Go.Compare will pay the first £250 of any claim. The company claims to have paid out £6.2m to customers doing exactly that between 2019 and 2023.

The results of my Go.Compare search for home and contents cover were illuminating. The cheapest policy I was offered was £236 with a company I had not come across before: Policy Expert. I’m very wary of signing up to companies you can’t seem to phone up, so that was out. Sky offered cover for £300 but I started to lose the will to live trying to fathom out the website to check whether our bikes were included. The price comparison sites don’t always pass on the fact that you want to include bikes away from home to the insurer, so I always check before buying a policy.

In the end I opted for the third cheapest quote, from Tesco Bank, which for £309 a year was offering the same cover but has a call centre. We have a £350 excess – but will ask for the first £250 from Go.Compare in the unlikely event that we make a claim. Making the policy joint with my wife actually brought the price down by a further £7, and I explicitly asked not to be put on auto-renew. I never buy legal expenses cover because, in my experience, it is almost impossible to claim upon unless you have a near-certain claim.

We paid in one payment but would have gone with MBNA/Lloyds Bank if not, as it offers buyers the option to pay over 12 months interest-free. The upshot? We are paying less than last year and have avoided the 25% increase.

For me, this has become a well-worn path. In February this year, Churchill announced that it was set to increase our car insurance in March from £215 to £282 a year – a 31% increase. This for a 2006 Toyota Avensis estate that, while still a worthy performer, has covered more than 209,000 miles and is worth very little.

In that case, Go.Compare again gave us some options that were around the same cost or cheaper than my current deal. Having applied the same considerations as above (for example, being a little wary if I have not heard of a company or it is hard to contact), we opted to switch to Halifax for £240 a year. It offered European cover and a protected no-claims bonus as before – and was only a shade more expensive than last year, which is not bad considering that the trade body the Association of British Insurers said recently that average motor premiums rose by 34% last year.

However, this is small change in comparison with the amount I have just saved my 85-year-old mother on her car insurance. She has a 2019 Fiat Panda and still pootles around the back roads of north Essex a few times a week. Her insurer LV= has just written to her to say that she will have to pay £1,242 to carry on her cover – more than twice the £605 she paid this time last year. Again, she hasn’t made a claim, but she is obviously a year older.

For her cover, I used Confused.com to compare prices, and we have got this year’s cost down to £725 a year. The cheapest firm was the RAC (online only) at £690 – however, the RAC is not a favourite company in her household after it left her sitting on a roadside for six hours a few years ago. Instead, she has gone with Co-op Insurance at £725 a year – a full £500 less than LV= wanted to renew. Not a bad return on 20 minutes’ work.

An ABI spokesperson said: “The specific risks insurers cover, and sometimes the products they offer, may change from year to year - so we would always recommend shopping around when looking for insurance. However, it’s really important to make sure you’ve got a policy that meets your needs, not just based on price.

“We welcomed and supported the FCA’s rules on pricing for home and motor insurance. Under the rules, when existing home and motor insurance customers renew their insurance policy, the price charged by the insurance provider cannot be more expensive than the price that they charge an equivalent new customer for the equivalent policy.”