The government has said there is "no obligation to suspend business" during the national mourning period.

But it added that some businesses "may wish to consider closing or postponing events, especially on the day of the state funeral".

That, however, would be "at the discretion of individual businesses", the guidance concluded.

Here we take a look at some of the UK's big businesses and find out what their plans are.

What to expect today as Queen leaves Buckingham Palace for final time - live updates

Supermarkets and department stores

• John Lewis said its department stores and Waitrose shops will close on the day, but an exception might be made for a "very limited number" of Waitrose stores on the route of the funeral procession, but even these shops will close for the funeral itself
• Sainsbury's and Argos stores will be closed, including online deliveries and Argos fast-track delivery. Convenience stores and petrol stations will be open from 5pm until 10pm. Select stores in London will open to those attending the funeral in person
• Aldi stores will close for the day
• Lidl stores will also be closed
• Tesco's large stores will be closed all day. Express stores will be closed until 5pm
• M&S says stores it owns will be closed all day with "some limited exceptions". There will be no customer delivery services. A small number of stores in London will be open to serve those queuing to pay their respects to the Queen but these will close by 10.30am and remain closed for the day, except for the four stores closest to Westminster Abbey and St George's Chapel, Windsor, which will reopen after the funeral. Franchise partners in travel hubs and public service locations such as hospitals are likely to remain open
• Co-op stores will be closed until 5pm apart from some in central London and towards Windsor, which will remain open during the day to serve those who are part of the funeral. Online orders and deliveries will start again at 5pm
• Asda will close its stores by midnight on Sunday and will reopen at 5pm on Monday 19 September. There will be no online deliveries on Monday
• Morrisons supermarkets will be closed all day but petrol stations will reopen at 5pm
• Iceland stores will be closed
• Harrods' department store in London's Knightsbridge and all its other locations will be closed

More on the Queen:
How can you see monarch lying in state?
Football matches to resume
What happens next and what changes?

Shopping centres

• Overgate Shopping Centre in Dundee will open as normal, but individual retailers will choose whether they open or close their shops
• St James Quarter in Edinburgh will be closed with only a small number of food and beverage-related outlets opening later in the day. The Edinburgh Style and student evening events will also be postponed
• Landsec said its shopping centres will observe bank holiday opening times but retailers will make their own decision. Landsec's retail spaces include Trinity Leeds, Bluewater in Kent, White Rose Centre in Leeds, Gunwharf Quays in Portsmouth, St David's Dewi Sant in Cardiff, Junction 32 in Yorkshire, Braintree Village in Essex, Buchanan Galleries in Glasgow, Lewisham Shopping Centre, West 12 Shopping Centre in Shepherd's Bush and others
• Westfield London and Westfield Stratford are likely to remain open, although a number of stores within them will close for the day
• Manchester's Trafford Centre said its plans had not been finalised but any updates would be published on its website
• Hammerson's shopping centres will be open on Monday and a number of them are expected to show the funeral on screens, a spokesperson said. Hammerson's shopping centres include the Bullring and Grand Central in Birmingham, London's Brent Cross, Highcross in Leicester, Bristol's Cabot Circus, and Croydon's Centrale & Whitgift
• British Land said its retail places would remain open but a number of retailers were expected to close and shoppers should check with them individually. British Land's retail centres include Meadowhall in Sheffield, Whiteley in Fareham, Fort Kinnaird in Edinburgh, Drake Circus in Plymouth, Giltbrook in Nottingham, Mostyn Champneys in Llandudno, and Forster Square in Bradford

Sky News has also asked Eldon Square in Newcastle, Braehead in Scotland, Victoria Square in Belfast, Metrocentre in Gateshead for their plans.

Retailers

• Primark stores, depots and head office in the UK will be closed
• Apple stores across the UK will reportedly close for the day
• Lakeland will be closing all of its operations, including its stores, for the day
• All WHSmith High Street stores will be closed for the day. All UK WHSmith Travel stores will be closed for at least the duration of the funeral
• Halfords stores, garages, and support centres will be closed, and Halfords Mobile Experts will not be operating. A spokesperson said that any customers who have booked appointments in stores, Autocentres or with National Tyres will be contacted to reschedule
• All Next stores will be closed for the day
• Zara stores will be closed
• Waterstones stores will be closed
• Joules stores will be closed
• Toolstation will close all 556 of its UK stores
• L'Occitane will close all of its UK stores
• French Connection stores will be closed
• Pandora will close all of its 202 stores in the UK
• Cook will close its stores
• B&Q will close its stores, also temporarily suspending click and collect and home delivery
• Wickes will close all its stores, as well as customer care, its support centre, click & collect and distribution centre operations, along with home delivery services
• IKEA's UK stores will be closed
• Currys UK stores will be closed and nothing will be delivered to customers on the day of the funeral
• Poundland will close its 770-plus stores in the UK
• Jollyes will close its 80-plus pet food and accessories stores in the UK
• River Island stores will be closed
• Matalan stores will be closed
• Cineworld cinemas in the UK will be closed
• Wilko stores will be closed
• Pets At Home stores and Groom Room salons will be closed. Some vet practices will remain open but check ahead
• JD Sports will be closing all of its UK stores and offices
• The five RHS gardens at Bridgewater, Wisley, Hyde Hall, Harlow Carr and Rosemoor will be closed, including garden centres
• DFS will close its stores, deliveries, customer support and manufacturing operations
• H&M stores in the UK will be closed
• Dunelm will close its 177 stores, also pausing delivery, click and collect, and customer services
• Greggs said its shops would be closed all day though a small number of franchise sites may remain open
• McDonald's restaurants across the UK will be closed until 5pm

Sky News has also asked Boots, Clarks, Sports Direct, Robert Dyas, Superdrug, Card Factory, and TK Maxx for their plans.

Post

Royal Mail has said its services will be suspended on the day of the funeral, but the picture is a little more complicated at the Post Office.

The Post Office has 11,500 branches but only 114 of them are directly managed by the Post Office - those 114 will be closed for the day.

Around 2,500 branches are run by the likes of WHSmith, Tesco, Co-op and Spar, and these businesses will decide on their plans, although a Post Office spokesperson said it was "likely" most of these branches would also be closed.

They added: "The rest of our network of branches are operated by independent postmasters and typically are located in convenience stores. It will be the postmaster's decision whether to open on the day.

"On weekends, we usually have around 4,000 branches open and would normally expect a similar number to be open on a regular bank holiday.

"However, it may be that some independent postmasters, who would normally open their branch on a bank holiday, decide to close their branch on 19 September to mark the passing of Her Majesty."

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Do employers have to give staff the day off?

The Department for Business, Energy and Industrial Strategy has said the day of the Queen's funeral will operate in the same way as other bank holidays.

There will be no statutory entitlement to time off, although employers can include it as part of a worker's leave entitlement and employers are encouraged to "respond sensitively to requests from workers who wish to take time off".

Some of the retailers who spoke to Sky News for this article said staff who had been rostered to work on the day of the Queen's funeral would still be paid in full.

Some said that, as the day of the funeral is now a bank holiday, they would give staff an additional day in holiday entitlement.