The Best Online Casinos in the UK

Welcome to Casivo! We are here to take the hard work out of finding the best online casinos in the UK. With so many casino sites and bonuses to choose from, deciding where to play can be difficult. We have tried and tested every online casino in our top list, taken a good look at their games selection, banking methods and of course, the welcome bonus. Safety is our number one priority and each casino published on this page is regulated by the UK Gambling Commission.

Best Online Casinos 2020

No Wageringbetfred logo 140x19
50 Bonus Spins
Paid as Cash
Facts - Betfred Casino
Launched:
July, 2014
UK License:
Live Chat:
Paypal:
Play in £:
Min Deposit:
£10
Rating:
4.9/5
Introduction
Betfred is a name you’re probably familiar with, due to their huge success in the sports betting market. But we’re here to tell you about a much newer offering from the brand - their online casino, Betfred Casino. Get 50 wager-free bonus spins when you sign up and make your first deposit today.
Welcome Bonus - Casino
Bonus Spins:
50
Wager requirements:
0x
This promotion is only for customers who have not previously transferred into Betfred Casino. A minimum of £10 must be transferred into the Casino before any stakes will qualify for this offer. The minimum and maximum bonus awarded will be 50 Free Spins. There are no wagering requirements attached to any winnings received from the Free Spins. - T&C Apply
666 casino logo casivo uk  140x31
100% up to £66
66 bonus spins
Facts - 666 Casino
Launched:
September, 2017
UK License:
Live Chat:
Paypal:
Play in £:
Min Deposit:
£20
Rating:
4.7/5
Introduction
This devlish online casino is a brand from the extremely popular White Hat Gaming company. With such a name behind it, you can guarantee high quality and a great online platform from 666 Casino. Licensed and regulated by the UK Gambling Commission, it's a great option for players looking for loads of great value while playing in a safe environment.
Welcome Bonus - Casino
Bonus:
£66
Bonus Percentage:
100%
Bonus Spins:
66
Wager requirements:
35x
New players only. One bonus offer per player. Min deposit £20 Max bonus bet £5 Bonus offer must be used within 30 dats and bonus spins within 10 days, otherwise any unused shall be removed. Bonus funds are 100% of your first deposit up to £66 plus 66 bonus spins on Book of Dead slot only, and 50% of deposits 2-6 (incl) up to £66 Bonus spins winnings are credited as casino bonus and are capped at £50 Bonus funds are separate to Cash funds and are subject to 35x wagering the total of bonus plus cash. Only bonus funds count towards wagering req. Terms apply. BeGambleAware.org - T&C Apply
mrfavorit black
100% up to £25
+ 25 Bonus Spins
Facts - MrFavorit Casino
Launched:
August, 2019
UK License:
Live Chat:
Paypal:
Play in £:
Min Deposit:
£20
Rating:
4.7/5
Introduction
MyFavourit is one of the newcomers in the online casino world, and they've started with a bang. With thousands of games to choose from, plenty of regular promotions and of course a great welcome bonus for new players, be sure to check them out.
Welcome Bonus - Casino
Bonus:
£25
Bonus Percentage:
100%
Bonus Spins:
25
Wager requirements:
35x
New players +18 only. Min deposit £20, 35x wagering applies to match up bonus and spins. Offer valid for 1 week. Full terms apply. - T&C Apply
casushi logo casivo uk 140x49
100% up to £50
50 Free Spins
Facts - Casushi Casino
Launched:
January, 2020
UK License:
Live Chat:
Paypal:
Play in £:
Min Deposit:
£20
Rating:
4.7/5
Introduction
This quirky casino is brand new, launching in early 2020. Casushi guarantees an enjoyable playing experience, win or lose. The welcome offer is a great mixture of deposit match and free spins, and there’s a huge games selection to choose from.
Welcome Bonus - Casino
Bonus:
£50
Bonus Percentage:
100%
Bonus Spins:
50
Wager requirements:
40x
18+ new players only, minimum deposit of £20 required. Maximum bonus per player is £50 and 50 spins. 40x wagering requirements. Free spins only on Starburst. Bonus will expire within 30 days. - T&C Apply
NewKing Casino Logo 69x60
Up to £150 Bonus
+ 50 Bonus Spins
Facts - King Casino
Launched:
January, 2020
UK License:
Live Chat:
Paypal:
Play in £:
Min Deposit:
£20
Rating:
4.7/5
Introduction
King Casino is one of the newest brands from the online casino giants, Aspire Global. With monarchy branding and bonuses that are fit for royalty, players are very looked after at King Casino.
Welcome Bonus - Casino
Bonus:
£150
Bonus Percentage:
100%
Bonus Spins:
50
Wager requirements:
35x
18+. New players only. Min. deposit amount £20. Only for UK players. Max bonus 1st deposit £50 and 2nd deposit £100. Max wins from extra spins £100. Wagering required applies on all bonuses x35. 20 extra spins will be credited on first deposit and 30 extra spins on second deposit. Unused Extra Spins expire 24hours after being issued. Bonus must be wagered within 21 days of being credited. Full T&Cs apply. - T&C Apply
170608 videoslots 80x60
100% up to £200
+ Regular Promos
Facts - Videoslots
Launched:
June, 2014
UK License:
Live Chat:
Paypal:
Play in £:
Min Deposit:
£10
Rating:
4.7/5
Introduction
Videoslots is packed with games for all types of players, whether you love slots, table games or live casino. The welcome bonus is one of the biggest out there, and we're sure you'll enjoy the feel and experience of using their website.
Welcome Bonus - Casino
Bonus:
£200
Bonus Percentage:
100%
Wager requirements:
35x
18+. New Players Only. £10 minimum deposit. 35x Wagering Requirements apply. The 100% bonus will be paid in 10% increments to your account balance. Bonus balance is not playable. Please Play responsibly. - T&C Apply
21casinologo2 140x30
121% up to £300
+ Loyalty Rewards
Facts - 21 Casino
Launched:
February, 2015
UK License:
Live Chat:
Paypal:
Play in £:
Min Deposit:
£10
Rating:
4.8/5
Introduction
By joining 21 Casino you will be rewarded with a a huge 121% up to £300 first deposit bonus. They don't come much bigger than this, and with 21 Casino you can expect to find all of your favourite slots and games, as well as regular promotions.
Welcome Bonus - Casino
Bonus:
£300
Bonus Percentage:
121%
Wager requirements:
35x
18+ New players only. Min deposit £10. Bonus funds are 121% up to £300 and separate to Cash funds. 35x bonus wagering requirements apply. Only bonus funds count towards wagering requirements. £5 max. bet with bonus. Bonus funds must be used within 30 days, otherwise any unused shall be removed. Terms Apply. BeGambleAware.org - T&C Apply
New777 casino logo 74x60
100% up to £200
+ 77 Free Spins
Facts - 777 Casino
Launched:
December, 2019
UK License:
Live Chat:
Paypal:
Play in £:
Min Deposit:
£10
Rating:
4.6/5
Introduction
777 Casino is brand by one of the biggest online casino companies in the UK, 888 holdings. Already sporting an impressive portfolio of casinos, 777 Casino is no exception, with it's beautifully designed Vegas theme and generous promotions. Keep reading to find out everything you need to know about 777 and how to claim their welcome bonus.
Welcome Bonus - Casino
Bonus:
£200
Bonus Percentage:
100%
Bonus Spins:
77
No Deposit Bonus:
77 Free Spins
Wager requirements:
30x
1st deposit only • 14 day expiry • FreePlay (FP) wins credited as bonus & capped at the amount received, exc. JP win • Valid for selected games • Bonus wins capped at £500 • 30x wagering – req. vary by game • Bonus expires within 90 days • Withdrawal restrictions & full T&Cs apply - T&C Apply
888casino logo 60x60
100% up to £100
+ £88 FreePlay
Facts - 888 Casino
Launched:
February, 1997
UK License:
Live Chat:
Paypal:
Play in £:
Min Deposit:
£20
Rating:
4.6/5
Introduction
If you're searching for a leading UK gaming platform, then 888 Casino is the place to be. Having opened its doors in 1997, this online casino has picked up awards year after year.
Welcome Bonus - Casino
Bonus:
£100
Bonus Percentage:
100%
Wager requirements:
30x
New players only • Claim in 48 hrs • 14 day expiry • FreePlay (FP) wins credited as bonus & capped at £10, exc. JP win • Valid for selected games • Bonus wins capped at £500 • 50x wagering – req. vary by game • Bonus expires within 90 days • Withdrawal restrictions, T&Cs apply. - T&C Apply
queen play new logo 102x60
Up to £200 Bonus
+ 100 Free Spins
Facts - Queen Play Casino
Launched:
February, 2020
UK License:
Live Chat:
Paypal:
Play in £:
Min Deposit:
£10
Rating:
4.6/5
Introduction
Queen Play is a brand new casino site, launching in February 2020. Their royalty-themed brand is all about being fit for a queen, but fear not, the site is perfect for queens and kings alike. There’s plenty to like about this brand new casino, including their huge welcome offer. The generosity doesn't end after you've joined, their exclusive club rewards loyal and regular players with even bigger bonuses and promotions.
Welcome Bonus - Casino
Bonus:
£200
Bonus Percentage:
100%
Bonus Spins:
100
Wager requirements:
35x
18+. New depositing players only. Min. deposit £10. Max. bonus varies per deposit. Offer is only available in the United Kingdom. Wagering requirements are 35x. - T&C Apply

Criteria For The Best Online Casinos

We apply a strict criteria to each and every one of our online casino reviews, with no exceptions. We’re always on the look out for the best bonus casinos, but there’s more to it. Before being published on our website, each site is tried and tested by our experienced team. Only when an operator has ticked every box will they be listed as one of the best online casinos. Our testing process is outlined below.

1. Safety is Our Priority

Only casinos licensed by the UK Gambling Commission are tested and published on Casivo, ensuring the complete safety of our players. We also look at several other safety aspects, including encryption and the protection of your personal data.

2. Selection of Games

During our reviews, we are looking out for the biggest names in gaming software, including NetEnt, Microgaming and PlayTech, amongst others. This guarantees a good selection of both slot and table games, and says a lot about the casino itself, as these software providers only work with reputable operators. We hope to see progressive jackpot slots, and there’s extra points given if there is a great live casino on offer.

3. Deposit Methods

Online casinos have had to keep up with the development of new payment methods, including popular e-wallets like Paypal Casinos, Neteller, Skrill and even popular Cryptocurrencies. Operators should provide more than just Mastercard and Visa payment methods, for both fast deposits and fast withdrawals.

4. Fast Payout Casinos

Although we appreciate that there’s an element of processing involved in payouts, some online casinos can be far too slow in giving players their money. A big part of our online casino testing criteria is how fast the payouts are… We would expect most e-wallets to be within 24 hours and some providers also have fast track card transactions with certain banks. We only recommend casinos with fast payouts.

5. Customer Support

One of the less obvious, but still equally important aspects we look at is the quality and availability of customer support. No online casino is complete without a great service team, and although not every casino we recommend has 24/7 support, they all offer multiple ways to get in touch including live chat, email and telephone.

6. Design and User Friendliness

Every online casino should be easy to navigate and optimised for every device, whether you prefer desktop, mobile casino or tablet. We have tested each site on this page for usability, and the high scorers have user-friendly interfaces, seamless navigation and optimisation across devices.

Registering at an Online Casino

The process of signing up to a casino site is a relatively easy one, from start to finish, it takes about 5 minutes. With developing technology, operators are working on ways to streamline the registration process even more. We’ve outlined how to sign up with a casino below, and the steps remain the same regardless which device you’re using.

pick a casino

Pick a Casino

Use Casivo to compare all of the best online casinos in the UK and pick your favourite from the list. Your choice will completely depend on your bonus preferences, which has your favourite games, or just which takes your fancy. Rest assured that every casino listed on Casivo has been checked for licensing and safety.

visit site

Click Visit

Click ‘visit’ or ‘to the site’ depending on which page you’re looking at, and you’ll be transferred directly to your chosen casino, must of the time this will be to the registration page. This saves you time and the hassle of having to search for the brand yourself, we work hard to make everything as simple as possible for you.

register details

Register

The good news is that online casino brands don’t ask for any more details than they need, so the actual registration form is quite concise. You’ll be asked for your personal details like name and address, as well as email address and phone number, so have these things handy.

deposit

Deposit

Once verification has been complete, that’s when the fun can really start. You will need to select your preferred deposit method, provide the details like your card number or PayPal email address, select your deposit amount and you’re ready to start playing.

Online Casino Verification Process

The UK Gambling Commission is the governing body that regulates the entire UK gambling and betting industry. With such regulation comes a number of rules that casino operators must abide to, most of which you will hardly ever see as a player. However, one of the single most important regulations in place by the Gambling Commission is ‘Know Your Customer’, which is the player verification process.

What is Know Your Customer (KYC)?

As frustrating as it may feel when you just want to sign up and get playing, the Know Your Customer (KYC) process is designed to protect the players themselves, and is a legal requirement. Depending on the casino, you’ll be asked to verify yourself either straight after registration, when you make your first deposit or withdrawal, or even once you hit a particular threshold of transactions.

If you have your documentation readily available, KYC should be a relatively quick and painless process. You should expect, on a good day, to be verified within a few hours if you’re quick at your end. Most delays are usually caused by missing information, so try to avoid this. We’ve compiled a list of documentation required to complete KYC, but remember, you can be asked for any of of these things, so it’s best to have them all at hand.

KYC Documentaton

You will be asked to provide one, or several, of the following:

  • Photo ID (Passport, Driving License)
  • Proof of Address (Utility Bill)
  • Proof of Income (Payslip)
  • Affordability Checks
  • Bank Statements
  • Photo Evidence of Card
  • Telephone Confirmation
  • Deposit Limits

Choosing the Best Casino Sites

With competition heating up, online casino sites in the UK are having to work harder than ever to attract new players and retain them. This works in your favour, because one of the main ways that operators compete is through lavish welcome bonuses. Knowing which to choose can be hard, especially if you’re a beginner. Our complete guide to the best casino sites in the UK includes each and every welcome offer as well as a thorough review of each brand – making choosing an casino easy. Only when all of our criteria is complete and satisfactory do we then publish an operator on Casivo, so all that’s left for you to do is pick your favourite.

But comparing our options and making your choice of which site to play on completely depends on your preferences. Whether you prefer slots, tables, live casinos, there’s something for everybody. We recommend considering each casino bonus and welcome offer and decide which works best for you. For example, a generous first deposit bonus is perfect for players that want more bang for their buck, and free spins are great for those that would rather spend less.

the best casino 43794429

mobile casino

Mobile Casinos

Most online casinos have adjusted to the times and have adapted to mobile functionality. As a result, whether you’re playing on iOS or Android, you will enjoy the same seamless experience that you would have on PC or laptop.

This is all thanks to the development of HTML5 technology, now powering most mobile casinos. As well as a mobile site, many of the biggest operators also have a dedicated app which can be downloaded from the Apple and Google store.

live casino

Live Casinos

If you’re looking for the most realistic and immersive experience, look no further than live casino. With many new sites, you can unlock a world of live tables, real dealers and a true authentic land-based casino feeling like no other.

Live Casinos are growing in popularity as the social aspect allows you to interact with dealers and players. You can enjoy multiple variations of all of the popular table games, including Blackjack, Roulette and Baccarat, amongst others.

Welcome Bonuses at Online Casinos

Welcome bonuses are the biggest attraction to an online casino, with new players benefiting from generous offers for joining. They tend to come in a number of familiar formats, but will all be slightly different depending on the operator, and which you choose completely depends on your definition of value.

Some players may prefer a lower deposit match with equally as low wagering requirements, and others may prefer more generous bonuses with tighter terms and conditions. Either way, it’s important to know what’s on offer. We have outlined the most common welcome bonus types below.

First Deposit Match Bonus

One of the most popular of all, a first deposit match bonus is as simple as it sounds. Operators will give you 100%, 200% or even 300% of your first deposit up to a certain value. If you’ve got some money to spend, this can be extraordinary value as you can play with twice the amount.

Free Spins

Free Spins are most commonly offered 2 different ways. Some online casinos will give you completely free spins with no deposit after registration, while others will reward you with spins after you’ve made your first deposit. They’re a great way to familiarise yourself with the games and maybe even walk away with some money.

online casino welcome bonuses uk

No Deposit Bonus

Many sites will offer a free casino bonus, usually to the value of £5 or £10 for you to play before you spend. These bonuses are great as unlike a lot of free spins offers, they aren’t specific to one game. This is the best way to try a variety of games before you deposit any money.

Cashback

A less common welcome offer, but still available on the market, is a cashback bonus. In a nutshell, a cashback offer will reimburse you a percentage of your losses up to a certain value – e.g, 20% up to £100. These bonuses can be popular with some players as it’s actual cash, and you can try to win, but get some money back if you don’t.

paypal casinos

PayPal Casinos

PayPal is at the forefront of all online payments, including depositing and withdrawing with an online casino. Not only are your payments processed instantly, but you get your winnings within 24 hours, which is much faster than other methods.

Don’t worry about safety, PayPal have extensive security measures in place so that your personal data and financial details are kept private. PayPal is renowned for being the safest online payment provider.

pay by mobile

Pay By Mobile Casinos

This new breed of online casino allows you to make a deposit using your PAYG balance or your monthly mobile phone bill. Not only does this save you from having to remember long card details or logins, but it’s completely safe to use.

Although not accepted everywhere yet, it’s very common amongst new casinos, and the more established ones are also slowly adapting to this new way of paying.

What to expect from an online casino

Sites are going to continue getting better and better, and 2020 is going to be a huge year for the industry, with new casino sites launching regularly. We expect to see a further rise in player interactivity, otherwise known as ‘gamification’.

Gamification casinos are those that include levelling up, regular rewards, leaderboards and races, all designed to make the experience more fun for players. There’s also likely to be a further increase in the generosity of loyalty programmes and rewards for existing players, in a bid to compete with the new operators.

If you enjoy casino, there’s many reasons why you may prefer online over a land-based establishment. We’ve listed some of the biggest benefits of going online here.

Why Use an Online Casino?

  • There is never a queue or crowd at your favourite games, so you don’t have to wait around to have your fun
  • You can play on any device, at any time, without having to leave the house
  • There’s a hugely diverse selection of games
  • The welcome bonuses at online casinos are incredibly generous
  • Each online casino is regulated by the UK Gambling Commission, so you can play safely and enjoy your experience

Casino Software Providers

Behind every exciting slot and immersive table game is a team of software developers whose sole purpose it is to design the very best in online casino entertainment. With the rapid increase in new casino sites launching, the list of software providers is ever-growing, but there’s still some very popular market leaders behind some of the biggest and best slots in the world. We’ve created a brief guide below to familiarise yourself.

NetEnt

Around since 1966, this Swedish casino gaming provider is probably the biggest in the world. They are the name behind the likes of Gonzo’s Quest, Street Fighter 2 and many TV-based slots like Narcos and Jumanji. NetEnt are a favourite amongst all types of casino player, whether vastly experienced or relatively new to the scene, and they’re likely to continue dominating the market for years to come.

PlayTech

PlayTech have long been hailed the ‘Kings of Casino’, developing some of the most-loved casino games over the years. None more notable than the Age of the Gods series, which has multiple variations, including blackjack and roulette versions. They also sport the popular Superman series, including Man of Steel, Superman the Movie and Superman 2.

Microgaming

Microgaming were established in 1994, making them one of the longest reigning market leaders in the casino software world. They’re very well-known for their more stripped back and classic style Vegas slots, but they’re also the name behind the biggest jackot game out there, Mega Moolah, which pays out staggering sums of money sometimes reaching tens of millions.

IGT

With nearly 500 games under their belts, IGT have one of the most impressive game portfolios to date. You’ll find a bit of everything with these guys, from 3-reel classics to exciting and interactive video slots. Many of their titles are featured in land-based casinos, including the likes of Golden Goddess, Lobster Mania and Pharaoh’s Fortune.

Megaways
Why Bonzana?
This Big Time Gaming slot is a real favourite amongst online casino players. With it's Megaways feature, there are over 1,000 ways to win, and you can land up to 10,000x your stake in the bonus round. You can enjoy Bonanza at All British Casino.
Fun
Why Starburst?
Starburst is a relatively new to online casinos, but has quickly become one of the most popular with players. The Starburst wild re-spin can result in huge wins, and the gameplay and slot design is enjoyable and easy even for beginners.
Classic
Why Rainbow Riches?
By far the biggest title to come from Barcrest Gaming, Rainbow Riches has been one of the most played online casino games for many years. Its 3 unique bonus rounds add interactivity to your game play, and can be great balance boosters.
Volatile
Why Book of Dead?
Book of Dead is famed for it's high volatility, making wins less frequent, but when it pays, it really pays. The free spin bonus round and expanding symbol feature can see you win up to 10,000x your stake, so it's no wonder why it's so popular with players.
support

Our Commitment to Responsible Gambling

The most important thing about playing at an online casino is that it should always be fun and safe. Gambling addiction is a serious problem, and something we at Casivo work to overcome by only working with operators licensed by the UK Gambling Commission.

If you feel like you are spending more than you can afford to lose, or are experiencing financial difficulty, we highly recommend utilising safe gambling controls such as deposit limits, cooling off or self exclusion. For help with a gambling addiction, or if you’re worried about your habits, call The National Gambling Helpline on 0808 802 0133.

UK GAMBLING COMMISSION LICENSES

All online casinos in the UK must be licensed by the UK Gambling Commission. The commission is there to ensure that casinos stay safe and fair for players, regulating all games, promotions and competitions. Another important feature of this licensing is the responsible gambling protection, providing endless support for vulnerable players. Any disputes with operators are raised with, and resolved by, the UK Gambling Commission, who work as an independent party.

Casivo only recommend legal, fully licensed and regulated online casinos. We have thoroughly assessed each website for safety, security and licensing, and only publish the very best. Playing elsewhere puts you and your personal data at risk, so we highly recommend that you avoid doing so.

Why a Licensed Casino?

  • Fairness is guaranteed
  • Safe personal data
  • Responsible gambling controls
  • Dispute resolutions
  • Payment safety
  • Customer support

No Wagering Casinos: What Does It Mean?

As online gambling becomes more popular, brands are working harder than ever to attract and retain players. With this came the birth of no wagering casinos, offering players some of the best bonuses we have ever seen. There is now a number of online casinos without wagering requirements and they are some of our favourites. But what does it actually mean to have no wagering? We’ve explained it below and outlined the perks of playing at these casinos.

What is a No Wagering Casino?

A no wagering casino simply means that there are no turnover requirements on any bonuses players receive. The best online casino welcome bonus with these operators is free spins, and the good news is that anything you win on these spins are paid as cash for you to do what you want with. No wagering casinos are quite a new concept but are becoming more common and are a big favourite amongst players.

Online Slots With No Wagering Requirements

We all love to play online slots, so how great would it be to do so with a bonus with no wagering requirements? Similar to online casinos, slot sites are also offering slots bonuses with no wagering, or much lower than ever before. This means that you can enjoy your favourite games and have a better chance of winning than ever before. What’s no to like about that?

Low Wagering Casinos in the UK

The increase in no wagering casinos is forcing many other operators to rethink how they offer bonuses. A few years ago, many welcome offers would have 50x or 60x turnover in their terms and conditions, now it’s rare that we see much higher than 35x. This is great for players as it means that there’s an increased chance of actually walking away with some money from a casino bonus.

The Best Casino Sites Without Wagering

So where do you find the best casino sites with no wagering? Don’t worry, we’ve got you covered. Each of our reviews include complete information about the welcome bonus, what the wagering requirements are and any other terms and conditions attached. Look no further than Casivo to find your next casino site with the best bonuses.

Online Casinos FAQs

QA

✅ Why should I trust Casivo?

Casivo is run by a team with years of experience within the gambling industry. By that, we have developed our own framework to make casino reviews as objective as possible. All the reviews you find at Casivo are thoroughly tested and verified before recommendations. If you have any complaints or questions, please feel free to contact us.

✅ How much is a casino bonus worth?

Usually, depending on the type of bonus, a casino bonus is worth a certain percentage based on your deposit. The extra money you receive from the casino is considered as bonus money, which you often have to wager. With a wager requirement of 35 times the bonus amount, about 50% of the value gets converted to real cash. However, only 20% of the bonuses get converted due to the fact that some players win really big.

✅ What is return to player on a slot machine?

Return to player, often referred to as RTP, is a percentage that reflects how much you can expect in returns from a casino game over a long period of time. In terms of slots, a standard RTP is around 96%. This can be compared to the NetEnt slot Blood Suckers that has 98% in RTP or the classic casino game Roulette that has 97,3% in RTP.

✅ What is a progressive Jackpot?

Progressive jackpots are also known as pooled jackpots. It works in a way that several players from a number of casino sites play to win the big jackpot, which often exceeds several millions. Every lost bet from any player, further contributes in increasing the overall jackpot prize amount.

✅ Are slot machines rigged?

No. Slots are rarely developed by casino sites and cannot be controlled or adjusted in any sense by a particular online casino. Instead, slot machines and other casino games are developed by game providers that are under regulation by the UK Gambling Commission to ensure that the pay-out ratio and other factors follow the rules that are stated.