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The amount needed in savings is actually £62,500, not £62,000... which at today’s exchange rate is equal to $79,769.40.
Ideally you want to have a buffer of a few thousand dollars just in case of exchange rate fluctuations. For example, just 5 days ago, £62,500 was worth $80,100 and 10 days ago it was worth $80,300.
If you are using investments, they do need to be liquidated as you need to prove they are immediately accessible and can be withdrawn in cash at any time (with or without penalty).
As long as you have held the investments in full for at least 6 months, they can be used as cash savings right away after being liquidated.
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