Where are you putting your savings these days?

I'm a student and would like to stash the little money I have in a safe place until my degree program finishes. US high interest taxable savings, or lowered rate UK savings in rapidly devaluating currency (how does IRS find out?).

The IRS finds out because you report the interest on your US tax return and the account details on Form TD F 90-22.1.

I'm saving money I need in the next few years to a UK cash ISA and a regular UK saving account. Money for the longer term goes into a 60/40 mix of low expense stock/bond index funds back in the US. You must put UK interest on your 1040. You file the TDF90-22.1 if the total of your foreign accounts goes over $10k.

Assuming you're a US citizen going to school in the UK and you've been here less that 7 years out of the last 9 you'll be taxed on a remittance basis so US interest left in US accounts won't be taxed by the UK. That might be something to think about. I've been in the UK almost 3 years and I'm hoping to buy a flat soon so I'm saving for that in UK savings accounts as I don't want to deal with currency fluctuations.

To properly decide the best tax strategy you need to take into account your citizenship, residency, the level of your income, and if you are on a grant or stipend the nature of that too

Just a word of caution - if you have not been UK resident for 7 years yet you still lose the UK personal allowance & capital gains exemption if you do not report worldwide income & gains in the UK.

This could mean paying more UK tax than before so overall it needs careful thought.