Retailers made cut-price deals available online from midnight and many shops changed their opening hours to offer customers more time to snap up discounted stock, ranging from televisions to toothbrushes.
But there were no signs of the huge crowds which gathered last year, or the scuffles which broke out as customers fought over big-ticket items.
No-one, aside from journalists, turned up to Boots’ flagship store on Oxford Street as its doors opened at midnight.
Elsewhere moderate crowds queued outside some Tesco Extra stores, which opened at 5am, some being offered mince pies as they waited in the rain and cold.
As the shutters were raised and doors unlocked shoppers were seen walking calmly into the stores, while others waited their turn as security staff limited the number heading in at any one time.
Meanwhile, an online campaign was urging people to buy nothing and instead use Black Friday to hug a friend or ring their parents instead of rushing out to the sales.
Thousands of people have indicated their support for avoiding what is predicted to be the one of the busiest shopping days of the year, by signing up to “Buy Nothing Friday”.
The Facebook campaign, set up by Edinburgh-based Sam Machin, urges people to “Join the Revolution” and so far has more than 30,000 attendees.
Asda today said it was dropping the price of unleaded petrol - despite announcing earlier it would not take part in the Black Friday discount day.
It is knocking four pence off a litre of fuel across its 277 petrol stations for three days, and drivers can expect to pay 99.7ppl on unleaded and 103.7ppl on diesel.
The price cut takes the cost of a litre of unleaded petrol below £1 for the first time since 2009.
On Monday, Asda will revert back to its original price of 103.7p on unleaded and 106.7 ppl on diesel.
It is expected that customers could spend their way to the UK’s first £1 billion in online shopping day today.
Tesco, which opened many of its stores at 5am, had installed queuing systems and assured shoppers there would be enough security and stock following scuffles over limited numbers of items last year.
Ebay is expecting nine million Britons to visit its website today, Argos, Currys PC World and AO.com are all offering hundreds of pounds off selected items, while John Lewis has promised to honour its Never Knowingly Undersold pledge and match competitors’ prices.
Amazon.co.uk is offering its Fire tablet for £34.99, £15 cheaper than the regular price, as well as deals on televisions, video game consoles and Star Wars toys and £650 off a Gibson electric guitar, while those in the market for fine jewellery can snap up a white gold and diamond tennis bracelet for £3,500 off the regular price of £8,995.
Last year, Black Friday overtook Cyber Monday for the first time as Amazon.co.uk’s busiest day, when it sold more than 5.5 million items at a rate of 64 per second.
But things got off to a slow start on Oxford Street this morning, where midnight came and went without any hint of last year’s consumer chaos.
The Boots flagship store on Sedley Place was one of a handful of shops which opened extra early, advertising deals on huge posters by the shop entrance.
But the doors flung open to two waiting journalists and no customers.
Elsewhere Norfolk Police were on site at Blue Boar Tesco in Norwich in case of trouble, but the queue of around 18 people moved slowly and politely through the doors as they opened up.
The scene at Surrey Quays Tesco was more calm than last year, when police were called to reports of arguments breaking out.
Around 30 people waited in the queue before making their way into the store as security guards looked on.
Entrance to Tesco’s Western Avenue store in Cardiff was limited to 10 people at a time, as people waited in the rain.
The 100-strong queue at Tesco Extra in Kingston Park, Newcastle upon Tyne were assured the store had plenty of stock, as the shutters were raised at 5am.
In the run-up to this year’s event police warned shops to ensure they have carefully thought-out security plans in place for the sales following chaos at a number of stores across the UK last year when huge crowds grappled for cut-price televisions and other big-ticket items.
Experian-IMRG believes internet spending today will hit £1.07 billion, a 32% increase on last year’s £810 million - the first time that online retail sales in the UK will surpass £1 billion in one day.
The Centre for Retail Research expects a slightly more modest £966 million online but predicts total Black Friday sales including at bricks and mortar stores will reach £1.39 billion, with shopping over the entire weekend - culminating in Cyber Monday - to hit £3.49 billion.
Visa Europe predicts that shoppers will spend £721 million online on its cards today, up from £616 million last year.
However, consumer advocates warned that shoppers should exercise caution amid the rush for bargains.
Martin Lewis, founder of MoneySavingExpert.com, has warned that the majority of Black Friday deals “aren’t special” and advised shoppers to cross-check deals with items they actually need.
He said: “Above all, remember: if you don’t want something, don’t need it or can’t afford it, then don’t buy it.”
Shoppers at Tesco Extra in Cradley Heath, West Midlands, saw no repeat of last year’s chaotic scenes after being issued with tickets to enter the Black Friday section of the store.
Only around 40 people arrived at the shop before its 5am opening and the queue for items was estimated to be around a tenth as big as last year.