In the UK its easier to buy short term treasury's (Gilts) than T-Bills. Can be expensive for smaller amounts though, the larger the amount the closer you get to the bond market and the lower the cost.
Our TIPS (Index Linked Gilts) exempt price appreciation taxation, interest is taxed, so generally lower coupon versions are better as much of the returns will be via the inflation increase in the price. Nowhere near as broad as the US's TIPS offerings however
https://www.yieldgimp.com/index-linked-gilt-yields
Banks and Building Societies compete with that, so generally you might rate-tart around and move maturing bonds into alternatives as each bond matures
https://www.finder.com/uk/savings-accou ... rate-bonds
A rising problem however is state monitoring
https://www.companydebt.com/hmrc-tax-pr ... ompliance/ With your regular bank account banks have been put under pressure to report any suspicious activities without alerting the individual, in order to avoid such cases slipping through and the bank potentially losing its licence, the banks are reporting all transactions, which feeds into the Connect system. Despite being early days some already are having their accounts frozen, closed, or transactions blocked - such as when buying physical gold. If you deposit or withdraw even modest amounts nowadays the bank interrogates you for where the money came from or what you're going to spend it on ...etc. If you only have a single bank account and that's frozen, it leaves you in a hole.
Deposit protections are just 85K Pounds, 100K Euro (or Dollars). Another nice element is that with IBKR your protection is the US $500K level (up to $250K cash). FX charges are also way lower with IBKR
Fundamentally the UK is locking down, whilst pushing you away from the Pound/UK, a dangerous game as if alternatives become commonly used/preferred then that could leave the Pound sinking rapidly.
We have ISA's and SIPP's similar to IRA and ROTH.
Inheritance Tax (Estate duty) is way more punitive. Nowhere US $12.5 million exemption, instead its more around $450K, beyond which a 40% tax rate applies.
Gold legal tender coins such as Sovereigns are tax exempt. As is your primary home (excluding Council Tax (state) that is around $3K/year for the average family home I'd guess)
The US apply a 30% withholding tax, that is reduced to 15% under British (and Irish) tax treaties with the US. Don't know about Ireland but in the UK you can offset that against the income tax you'd pay, so if your marginal rate is 20% and you've already paid 15% US withholding tax, you just have a further 5% more to pay.
The EU pretty well stuffed us from holding US ETF's/Mutuals. I had hoped that Brexit would have freed us from that by now, but that's not the case. Our two main parties, Labour (like Democrats) but use red as their color, and Conservatives (like Republicans, but use blue) are both pretty much the same now, very Labour (Democrat) like, the likely election of Labour at the next General Election is inclined to see even worse taxation/wasteful spending and open border migrations, and where there's no real alternative for those that may be more of a Republican type mindset. Many of those that would generally vote Conservative will simply abstain.
Given things as they are and headed, I for one am more tempted to hold US dollars, along with gold, literal hard-cash self insured/secured, bumping up the stock side of things to compensate for the lack of cash deposit interest. For someone who started retirement perhaps at a 4% SWR, but where the ongoing withdrawal rate had declined to being 2%, then a 2% 30 year SWR from thirds each hard dollars cash/physical gold/stocks, historically since the late 1800's has been inclined to end 30 years with the inflation adjusted capital value still intact. Whilst two thirds is literally in-hand (and stocks can be liquidated in T+2 time). i.e. entering a era of more a case of focus upon return of money rather than return on money.
Across the EU each member state (formerly country) have their own rules/policies, the EU however is pushing to have the additional Fed equivalent level above that i.e. another layer of taxation/costs. Where most members have been locked in by debt. I'm personally glad to be on the outside of that as even without that things may be bad enough as they are.