“Cocaine didn’t do anything for me”, wrote the Duke of Sussex in his 2023 autobiography Spare. “Marijuana is different, that actually really did help me,” he continued.

Both drugs are illegal in both the UK and the US – where Prince Harry currently lives.

Nile Gardiner, director of the right-wing Heritage Foundation’s Margaret Thatcher Center for Freedom, has sought the publication of the duke’s immigration files under freedom of information legislation. He says: “Harry decided to move to the US and entered without apparent difficulty in under two weeks.

“One would have expected that Harry’s immigration application would have included the same detailed description of drug use as his book. Any omissions would be an extremely serious matter.

“The case is bigger than one person—it is about whether the US government is following the law.”

What exactly are the rules for UK visitors to the US – and do they differ if you are rich and famous? These are the key questions and answers.

How does a person get permission to enter the US?

The vast majority of British travellers enter using the Electronic System for Travel Authorization (Esta). This automated system usually grants permission to travel to the United States for business or tourism for stays of up to 90 days without a visa. The permit lasts for two years or until the passport expires.

The scheme came into effect in 2009 and involves paying a fee of $21 (£16) after completing an online form. The official site is esta.cbp.dhs.gov. Be warned that a number of “lookalike” sites are out to catch careless applicants to search online for “Esta” – if anyone asks more than $21, it’s a scam.

What could exclude me from Esta?

Many transgressions will make a traveller ineligible for Esta. The principle is that you should not “pose a threat to the welfare, health, safety, or security of the United States”. There are three which are particularly likely to rule out a traveller from the “fast track” route to the US:

Let’s take each one of those in turn. Drugs?

Millions of British people use illegal drugs. The latest Crime Survey for England and Wales says one in 11 people aged 16 to 59 years “reported using any drug in the last 12 months”. That’s around 2.9 million people.

Add in people from Scotland and Northern Ireland, those under 16 and 60-plus and drug users who did not confess to the survey, and 5 million looks a reasonable figure for a year. And once those who have ever used an illegal drug are included, 20 million may well be a conservative estimate.

What are the options for drug users, past and present, for permission to visit the US?

Legally, they are ineligible for an Esta and must apply for a visa. Travellers should not provide misleading answers when applying for any permit.

In practice, many people who have used illegal drugs will tick the “No” box on the assumption that the US government will never find out about a youthful indiscretion.

But Nacro (the National Association for the Care and Resettlement of Offenders) warns: “It may be that you decide to withhold details of you criminal record and successfully travel to, or via, the US under the Visa Waiver Programme. It may then be the case that at some point in the future you need to apply for a visa to the US – perhaps because you take on certain employment – and you need to travel there for longer than 90 days, or you decide to emigrate.

“In order to apply for the visa, you will need to supply a copy of your Police Certificate which may disclose details of your criminal record which you had previously withheld. The US Embassy will retain details of your previous Visa Waiver and this may then give them grounds to refuse your new visa application for having previously lied about your criminal record.”

If I do admit to using illegal drugs, can I get a visa?

Probably not. The US authorities say an “alien” is “ineligible to receive visas and ineligible to be admitted to the United States” if the have violated “any law or regulation of a state, the United States, or a foreign country relating to a controlled substance”. There is some tolerance for an alien who committed only one crime, but plainly the Duke of Sussex broke the law at least twice – with cocaine, and with marijuana.

However, the law is focused on drug crimes for which the traveller has been convicted. Public admissions of use of illegal drugs constitute a grey area.

Are the rules ever waived for the rich and famous?

Of course. Just ask Sir Mick Jagger, convicted in the UK in 1967 for possession of amphetamines (yes, that was nearly six decades ago, but the US never regarded convictions as “spent”).

Sir Paul McCartney spent nine days in a Tokyo prison for marijuana possession in 1980. Four years later, same offence, different location: the Beatles star was fined $100 for possession in Barbados.

The Rolling Stones made a 10-week tour of the US in 2024, while Sir Paul toured for eight weeks in the US in 2022.

Ed Sheeran, rather less of a geriatric, told Rolling Stone about his former drug habit in 2023. The following year he toured the US, and is rumoured to be returning in 2026.

What about being “arrested or convicted for a crime”?

If it “resulted in serious damage to property, or serious harm to another person or government authority”, you must declare it – even if you were never actually convicted.

This is one Esta condition that has been softened over the years; initially it applied for any arrest of conviction.

Nacro says: “This question relates to ‘moral turpitude’ offences. ‘Moral turpitude’ is a legal term in the US that includes offences relating to crimes against the person such as murder, manslaughter, rape, gross indecency, serious assaults, kidnapping; crimes against property such as arson, burglary, theft, robbery, fraud, receiving stolen property; and crimes against government authority such as benefit fraud, tax evasion, bribery, perjury.”

And previous visits to those nine countries?

According to the Esta form, you are ineligible if you have been present in one of the so-called “state sponsors of terrorism” – Cuba, Iran, Iraq, Libya, North Korea, Somalia, Sudan, Syria or Yemen – since the start of March 2011. Of these, Cuba is the only recognised holiday destination, and welcomes more British holidaymakers than all the rest put together.

The Independent understands that, in fact, the test for Cuba is whether you have been there since 12 January 2021.

As none of these countries would pass details of foreigners’ visits to the US authorities, many people who have been one or more of them will simply tick “No”. If, though, there is any evidence in a passport of such a visit, and it is discovered by a US Customs and Border Protection officer, you are likely to be sent back at barred from future visits.

Many UK visitors have circumvented the rule by “laundering” evidence of a visit to Cuba – obtaining a new, clean passport. Again, though, providing misleading information is a serious offence.

Any other ‘QTWTASBNs’ – questions to which the answer should be ‘no’?

How much of a pain is it to obtain a US visa?

You must fill in a much more detailed form and schedule an appointment in London or Belfast, as well as paying $185 (£143) – which is not refunded if you are turned down.