Linda Ellett, UK head of consumer markets at KPMG, said: ‘The wedding between the Duke and Duchess of Cambridge in April 2011 resulted in a monthly like-for-like retail sales hike of 6.31% , and weekly sales up as much at 17%, compared to the same month and week the year before.

‘Food and drink sales are the natural winners during times like these, as people come together and look to make the most of the moment. Indeed, UK publicans will be keen to make the most of extended trading hours this weekend.’

 Yael Selfin, chief economist at KPMG, added: ‘One of the more significant boosts to the UK economy will come from a rise in tourism, particularly given Meghan Markle’s American background. Coupled with the weak pound and a strong US economy, we are likely to see a jump in US tourism spend this summer.’

However, budding home entrepreneurs looking to make the most of their closeness to the route of Saturday’s Royal Wedding should be aware that HMRC will be looking for any undeclared income.

Nimesh Shah, partner at Blick Rothenberg, said: ‘Residents of Windsor will naturally find their properties in high demand this weekend. The rise of websites such as Airbnb demonstrates the popularity of short term lets and taxpayers should bear in mind that if potential customers can see their advertisements online, so can HMRC.’

Two bedroom homes in Windsor are renting for more than £3,000 a night while it is rumoured that properties with a room with a view have been renting for up to £15,000 a night. International broadcasters have allegedly paid more than £300,000 for rooms overlooking the route on Saturday. Shah said: ‘Even a relatively small amount of additional income can lead to a tax liability; however, two new annual allowances were introduced last year which can help with such situations. The trading allowance exempts the first £1,000 of trading income per annum and would cover, for example, selling strawberries or bottled water from outside your home.

‘The second allowance covers the first £1,000 of rental income, which would include income from letting out parking spaces or driveways to eager watchers. For those individuals renting out rooms in their own homes, the income can be tax free provided it doesn’t exceed certain thresholds.

‘The rent-a-room scheme generally applies to owner-occupiers and tenants who receive rent from letting furnished accommodation in their only or main home but can also be claimed by those running bed and breakfasts or guesthouses. The relief is separate to the rental income allowance and the two cannot be used together.’

While weddings are on everyone’s minds, Saffery Champness is warning that for those rural, estate and farm businesses that are in the wedding market – by providing rooms, barns, marquees, chapels, fields or woods for ceremonies – HMRC has been adopting an increasingly hard-line approach to VAT compliance, taking some of the shine out of the occasion.

David McGeachy, a partner and member of the firm’s landed estates group, said: ‘The passive, exclusive letting or license of land or property, such as a room or a marquee, without any further engagement by the owner, should be VAT exempt, assuming no option to tax has been made by the owner.

‘VAT is only due when additional services are added to the extent that those elements mean the overall package becomes a vatable one. However, HMRC has been successful over recent years in deeming the supply of the venue to be standard rated for VAT as part of a package of wedding services, with the Tax Tribunal also ruling to this effect.’

The Blue Chip Hotels Case in 2016 and 2017 was one such test of the system where HMRC was successful, and where it was found that if the room was provided with a right to hold a civil wedding ceremony then this, in itself, meant there was no simple passive letting of land and so VAT was liable at the standard charge of 20%.

McGeachy cautioned: ‘In a long line of cases, businesses have made the repeated mistake of underestimating the emphasis HMRC and the tribunals were placing on the presence of other elements overriding the passive letting concept. For example, if the owner receives a TripAdvisor review from the happy couple thanking them for being on hand, friendly and helpful, HMRC will argue that this cannot be a passive letting. There is a strong presumption that there must always be a wider service element in any wedding hire.’