The ongoing war in the Middle East has already started to hit Brits in the pocket with petrol prices rising due to the cost of oil. But as conflict rumbles on between the US and Iran, many people will be wondering how to protect their finances.

And because cash doesn’t rely on electronic payments or digital infrastructure, many will see it as a safe bet in the event of blackouts, cyber attacks, or even war. The European Central Bank has now revealed how much money is worth keeping in the event of a crisis.

The bank says Russia’s 2022 invasion of Ukraine, along with the 2008 financial crash, 2014 Greece debt crisis, and the Covid pandemic led to an “immediate and extreme surge in cash acquisition by the public”.

It reports: “Russia’s full-scale invasion of Ukraine in February 2022 triggered a significant surge in cash demand, concentrated in several neighbouring countries.

“This is a common response to the pervasive uncertainty that armed conflicts and geopolitical tensions introduced regarding institutional stability, state capacity and the resilience of critical infrastructures.”

It says the demand was mainly driven by countries such as Estonia, Latvia, Lithuania, Slovakia and Finland. The bank says it led to many authorities suggesting that families keep a cash reserve in case of an emergency.

That amount it says is often between €70 (£60) and €100 (£86). The bank explains: “Cash offers certainty concerning its nominal value, immediate access and privacy. Heightened loss aversion during crisis, coupled with varied individual perceptions of stability, make cash a tool for satisfying risk-averse individuals’ demand for direct liquidity insurance.”

The ECB also points out that during the Iberian blackout last year, card use dropped by 54 percent, while there was a drive for not just €10 and €20 notes but larger denominations such as the €100. Juan Carlos Galindo, a cybersecurity expert, told Larazon that now is a good time to get cash.

He however insists that most money is “digital” and that banks only hold around 10 and 20 percent of funds in cash. He warns there would not be enough banknotes should everyone try and withdraw all of their money at once.

He says this could lead to temporary restrictions or capital controls to help maintain financial stability. However, maintaining a small cash reserve means you could, the ECB says, keep going for 72 hours, the time it estimates it would take for major infrastructure to recover.

People are however urged not to replace their bank with cash, being reminded it’s a “preventative measure, not a substitute for the financial system”. And any cash reserves should be kept in a safe and accessible place, the expert says.