LONDON, Jan 17 (Reuters Breakingviews) - Bank chief executives like JPMorgan’s (JPM.N) Jamie Dimon almost always welcome higher interest rates. But as American and British lenders await tighter monetary policy in 2022, the benefits may be even larger than usual. Investors expect the U.S. Federal Reserve to raise rates three or four times this year, based on money-market prices, while the Bank of England already started tightening late in 2021 read more . Because bank lending rates tend to move up faster than short-term funding costs, more expensive money generally means better margins. Yet this tightening cycle is different to previous ones. Customers have parked an unprecedented amount of money with banks as lockdowns curtailed spending and governments doled out cash. The 25 largest U.S. banks had $11.2 trillion of deposits in December, up 38% from 2019 according to Federal Reserve data. Britain’s four biggest lenders - HSBC (HSBA.L), (0005.HK), Lloyds Banking Group (LLOY.L), NatWest (NWG.L) and Barclays (BARC.L) - held a combined 2.7 trillion pounds of customer cash in September, 20% more than pre-pandemic levels. Rather than lending that money out – total loans are up just 3% on both sides of the Atlantic – banks have parked much of the extra liquidity with central bank. Take Bank of America (BAC.N). As of Sept. 30, the group run by Brian Moynihan had $251 billion of interest-bearing reserves with the Fed and other central banks, double the pre-pandemic level. Those assets are earning next to nothing but will yield more immediately as official interest rates rise. The upshot is that banks’ rate-hike bonus should be much more pronounced. For instance, UBS analysts estimate that a 200 basis-point Fed hike over the coming years would lift U.S. net interest margins by 41 basis points. That’s three times higher than the boost banks received from the same increase in official interest rates between 2015 and 2018. Similarly, Lloyds in September estimated that a 25 basis-point rate increase would boost its net interest income by 225 million pounds. Back in 2018 the UK lender pegged the benefit at just 76 million pounds. Higher borrowing costs are not unalloyed good news. They will push up loan defaults and cool markets which have produced record-breaking investment banking revenue. The surge in excess deposits may also swiftly recede. In the short term, though, an unusually large rate-hike bonus gives Dimon and his rivals yet another reason to smile. Follow @liamwardproud on Twitter CONTEXT NEWS - The Refinitiv United States Banks Index rose by 9% between the start of 2022 and Jan. 14, compared with a 2% fall for the S&P 500 Index. - The Refinitiv United Kingdom Banks Index rose by 14% over the same period, while the FTSE 100 Index increased by 2%. - The 25 largest American banks had $11.2 trillion of deposits at the end of 2021 compared with $8.1 trillion at the end of 2019, according to Federal Reserve statistics.