Sticky Bonuses at UK Casinos

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A sticky bonus is a type of promotion that can be commonly found at a UKGC-licensed online casino. It is a non-cashable bonus that merges the deposit and the bonus amount together into a locked balance.

Players will need to meet specific wagering requirements to unlock any potential winnings that may be obtained.

These bonuses have been around since the very beginning of the online iGaming industry, making them very familiar and easy to recognise.

Although non-sticky options are usually more common, they can be found and can be more advantageous than their counterparts.

Still, this guide will provide everything that must be known about sticky bonuses. It will reveal what they are, how they must be used, and detail the pros and cons that can come with them.

Continue reading to ensure they are fully understood.

What Defines a Sticky Bonus for UK Players?

A sticky bonus for UK players is where the deposit and the bonus part of the deal are “stuck” together.

A player using their bonus will see their deposit and the bonus become combined, meaning any winnings that are obtained can only be released once both parts have met the wagering requirement of the promotion.

As both parts need to be met, they differ from other types of common bonus offers that can be provided by the best UK operators.

Although still widely available across the UK, it is not uncommon for operators to keep the wagering requirements separate and only be required to be met on the bonus part.

If both parts of the wagering requirements are not met when using a sticky bonus, any potential winnings that can be obtained will be locked. Players will not be able to claim them until they meet the conditions that have been set.

Sticky bonuses have become increasingly popular with UK players who seek larger initial bankrolls.

These promotions will often feature larger deposit match percentages, providing additional value. This can make them more appealing, as players have more funds to play with immediately than with other bonuses.

How Sticky Bonuses Compare to Other Bonus Types

Sticky bonuses can work very differently from other types of UK online casino bonuses that are available. Let’s take a look at some of the common options and how they differ:

Sticky Bonus

As highlighted, a sticky bonus is a promotion that sees the bonus amount credited to the player’s account as credit but cannot be withdrawn as cash.

It remains locked to the account until the wagering requirements of both elements are met, with winnings generated from the bonus typically withdrawable.

How do Sticky Bonuses Work?

A sticky bonus will be added to the player’s balance, but it will remain separate from the cash balance. Any real money deposit will be locked with it, meaning the entire balance will then be subject to the wagering requirements that are in place.

An example could be: A player deposits £100 and receives a 100% sticky bonus (£100). The total balance is £200, but the £100 bonus cannot be withdrawn, and the deposit is locked until a wagering requirement (e.g., 35x the bonus or deposit + bonus) is met.

Winnings from bets placed with the bonus can be withdrawn after meeting requirements, but the bonus amount itself is deducted from the balance upon withdrawal.

Characteristics of a Sticky Bonus

A sticky bonus will typically exhibit the following characteristics:

• Higher Advertised Sums: Sticky bonuses often feature larger sums or higher match percentages (e.g., 200% or 300% match up to £1,000) to attract players. This makes them appear more generous at first glance.
• Restrictive Nature: The deposit becomes part of the locked balance, meaning players cannot withdraw their own funds until wagering requirements are fulfilled. This can feel restrictive, especially for players who hit a big win early.
• Wagering Requirements: Sticky bonuses often have standard or lower wagering multipliers (e.g., 35x or 40x the bonus amount) compared to other bonus types. This can make them appealing to high-stakes players or those planning longer play sessions, as the requirements may be more achievable relative to the bonus size.
• Game Contribution: Not all games contribute equally to wagering requirements (e.g., slots may contribute 100%, while table games like blackjack contribute 10% or less), which can extend the time needed to clear the bonus.

Why do Sticky Bonuses Appeal to Players?

A player in the UK typically favours a sticky bonus if they are categorised as a high roller or by those who enjoy prolonged playing experiences.

The larger bonus sums and potentially lower wagering multipliers make them attractive for those aiming to maximise their bankroll and play strategically.

Non-Sticky Bonus

A non-sticky bonus is credited once the player’s real money balance has been used. Once they hit £0, the bonus funds will then be added to their account. This part of the bonus will then be subject to the wagering requirements attached to the terms and conditions of the promotion.

How do Non-Sticky Bonuses Work?

A non-sticky bonus will only be active once a player’s account balance hits zero. They must use their real money funds first before they can trigger the bonus.

Any money that is won when using real money can be withdrawn immediately without trouble. Any winnings that are made from bonus funds will be subject to the wagering requirements that have been laid out. 

An example of a non-sticky bonus: A player deposits £100 and receives a 100% non-sticky bonus (£100). They play with their £100 first. If they win £500 and want to withdraw, they can do so without touching the bonus. If they lose the £100, the £100 bonus kicks in, with a wagering requirement (e.g., 40x).

Characteristics of a Non-Sticky Bonus

A non-sticky bonus will show the following characteristics to highlght its difference from sticky bonuses:

• Flexibility: The deposit is not locked, allowing players to withdraw winnings from their real money balance at any time without affecting the bonus.
• Wagering Requirements: Typically range from 35x to 50x the bonus amount, which may be slightly higher than sticky bonuses but are only applied to the bonus funds.
• Player-Friendly: Non-sticky bonuses are less restrictive, as players can access their real money winnings immediately.

Why do Non-Sticky Bonuses Appeal to Players?

Compared to sticky bonuses, a non-sticky bonus can be more preferred by players, especially with the strict regulations in place by the UK Gambling Commission (UKGC).

Players enjoy this type of bonus as they can withdraw funds more easily, especially if they have been made when wagering with their real money. These bonuses can offer more value depending on their playstyle, especially those who are more casual or hoping to win significant prizes early.

Unlock Bonuses

An unlock bonus is a type of casino bonus where funds are released incrementally. Players must meet specific wagering requirements or other conditions to be eligible. They are less frequently offered compared to others, but can still be found.

How do Unlock Bonuses Work?

An unlock bonus will not immediately be credited to a player’s account as playable funds when claimed. Instead, it will be unlocked when players wager a certain amount or complete a certain activity. This could be placing a number of spins, or achieving another milestone.

An example of an unlock bonus may look like: A player deposits £100 and is promised a £100 unlock bonus. They must wager £1,000 (e.g., 10x the bonus) to unlock the full £100, which is then credited as cash or bonus funds.

After the funds have been released, they may have to meet further wagering requirements or be eligible to withdraw any winnings immediately. It will depend on the offer and the casino’s terms.

Characteristics of an Unlock Bonus

The following are the characteristics of an unlock bonus:

• Gradual Release: The bonus is drip-fed, which can feel less rewarding upfront compared to sticky or non-sticky bonuses.
• Wagering Requirements: Requirements for unlocking can be high (e.g., 10x–20x the bonus amount), and additional wagering may apply to the unlocked funds.
• Task-Based: Some casinos tie unlocking to specific games, bets, or timeframes, adding complexity.

Why do Unlock Bonuses Appeal to Players?

An unlock bonus may appeal to players who are dedicated and desire prolonged playtime. They are also happy to commit larger sums of real money that allow them to meet the requirements that have been set. They do remain less popular than other bonus types in the UK, which is why they are found less frequently.

Flexi Bonuses

Flexi bonuses are almost rare in the UK, but they can still be found on occasion. This type of bonus will typically combine aspects of a sticky and a non-sticky bonus. Depending on the casino used, they can allow players to convert bonus funds into cash when they meet wagering requirements or offer partial withdrawals.

How do Flexi Bonuses Work?

A flexi bonus will be credited alongside a deposit (which can be locked), allowing players to use either for wagering. Once the wagering requirements have been met, a portion of the bonus may become cashable. Players may also be able to forfeit the remainder of the bonus by withdrawing winnings early.

An example can look like: A player deposits £100 and receives a £100 flexi bonus with a 40x wagering requirement. After wagering £2,000 (half the requirement), £50 of the bonus becomes cashable, or they can withdraw winnings but forfeit the remaining bonus.

Characteristics of a Flexi Bonus

A flexi bonus will typically feature the following aspects:

• Hybrid Nature: Offers a middle ground between sticky and non-sticky bonuses, providing some flexibility for withdrawals while retaining bonus restrictions.
• Wagering Requirements: Typically 35x–50x, similar to non-sticky bonuses, but the ability to convert funds incrementally adds appeal.
• Complexity: Terms vary widely, requiring players to read the fine print carefully.

Why do Flexi Bonuses Appeal to Players?

While very niche, flexi bonuses can be appealing to UK casino players because they offer a level of flexibility. They allow players to compromise large bonus amounts with the ability to make a withdrawal. Still, they remain uncommon and less preferred than sticky and non-sticky bonuses.

UK Licensing and Responsible Gambling Requirements

The UKGC has set out extremely strict regulations that UKGC-licensed casinos must adhere to when offering sticky bonuses to players. They have produced a clear set of rules to ensure players are kept safe and play responsibly.

Transparency in Terms and Conditions

Licensed casinos in the UK must provide clear, concise, and easily accessible terms and conditions for all types of bonuses offered to ensure players are not misled.

This will mean explicitly detailing how a bonus works, including that the bonus amount cannot be withdrawn as cash and that any deposit made is locked to the amount until the wagering requirements are met. These must be outlined, including the playthrough amount, game contributions, max bets, and time constraints.

A casino must detail these terms and conditions prior to a bonus being claimed, and they must be visible in a predominant position. They cannot be buried in the fine print or hidden where they cannot be easily found. 

Responsible Gambling Measures

Responsible gambling is at the forefront of the UK online casino industry, with the UKGC setting clear rules to encourage safe experiences. The prevention of harmful gambling remains a top priority, especially where bonuses are concerned.

With sticky bonuses, the UKGC has set out to make several tools available to players that licensed casinos must make accessible on their sites. These can include deposit limits, self-exclusion options, and reality checks to ensure players remain in control of what they are doing at all times.

Deposit limits will allow players to cap their spending over a selected time period, such as daily, weekly, or monthly. Self-exclusion tools will allow players to block access to their casino account for a period of time, while reality checks will allow users to keep track of how long they have been playing for.

UK casinos must have a page dedicated to responsible gambling to access these tools, with links to organisations if further help is required. Organisations can include:

• GamStop
• GameCare
• GambleAware

Common Sticky Bonus Terms & Conditions

A sticky bonus will come with many different terms and conditions that must be met for it to be used effectively. Below is a breakdown of the most common and typical T&Cs that can be found at most UKGC-licensed casinos:

Wagering Requirements

A sticky bonus will lock an initial deposit and bonus funds together, but the latter cannot be withdrawn as cash. Players must meet the wagering requirement of both if they want to withdraw any potential winnings that may have occurred when used.

As an example, a sticky bonus could appear as a 100% match up to £100 with a wagering requirement of 35x. Players claiming the bonus may deposit £100 to get the full amount (£200), but the additional £100 bonus will not be possible to withdraw at all. In addition, their £100 cannot be withdrawn until the 35x playthrough has been met.

Maximum Bet Limits

A sticky bonus will typically come with maximum bet limits. In the UK, players may only be able to place bets as large as £5 when using this promotion. This stops players from burning through the bonus quickly, protecting their bankroll and stopping high-stake spins from being manipulated.

Game Contributions

Many bonuses will be subject to game contributions. Slots will typically be worth 100% to the wagering requirement, whereas live dealer and table games may only be 10%-20%. Some slots, as can many other game types, can be worth just 50% or even be excluded from contributing to the bonus.

Jackpots and titles with a high return to player (RTP) rate may also be excluded from the bonus promotion, which is why it is essential to read the terms and conditions closely.

Time Limits

Sticky bonuses are subject to specific time conditions. In the UK, licensed casinos will typically provide players with between 7 and 30 days to meet the wagering requirements of the bonuses offered. These can vary between operators, while certain components may have different time requirements.

Players who fail to meet the requirements within the time that has been set will forfeit their bonus and lose any remaining bonus funds or any potential winnings that have been achieved during the period.

Withdrawal Caps

Some sticky bonuses can come with withdrawal caps attached to them, while some offer unlimited winnings.

It is not uncommon to see a bonus that has terms and conditions that suggest the maximum that can be won when using the promotion is £100 or just 5x the bonus amount. Again, read the T&Cs to ensure a full understanding of how the bonus operates beforehand.

Step-by-Step: Claiming a Sticky Bonus at a UK Casino

Claiming a sticky bonus at a UK casino can be very easy to complete. The following steps provide a fool-proof way of doing so when copied:

Step 1: Signing Up

Sign up for a chosen UKGC-licensed casino on our dedicated casino page. Enter all the required details (name, date of birth, address, email, phone number, etc.) and complete the identity verification checks. Some sites may require this at a later stage (such as withdrawing funds), but it is best to complete as soon as possible.

Step 2: Select the Bonus

Selecting the bonus at this stage may be a requirement. Players may have to tick a box, enter a code, or select a dropdown option to claim any available offers. It may appear as part of the registration process, or it may appear as part of the process when depositing funds into their account.

Step 3: Make A Deposit

At this stage, players should be making a deposit into their account. The UK provides many options, although credit cards are banned. Still, check the T&Cs of a bonus to see if there are any exclusions, as some payment methods may not be eligible.

Once a successful qualifying deposit has been made, funds will be added to the player’s account. These will be combined with the sticky bonus. Remember, they will be “locked” with them, meaning they cannot be withdrawn until the wagering requirements are met.

Step 4: Playing with the Sticky Bonus

As all funds are combined, players have a responsibility to keep track of their wagering progress. They must also be mindful of sticking to the terms and conditions that have been set out with the bonus, otherwise the promotion can be forfeited. Remember, max bet limits can exist.

Step 5: Withdrawing Funds

If players can, they can freely withdraw any funds once they have met the wagering requirements and have completed the Know Your Customer (KYC) checks. This is why it can be beneficial to do the verification checks as early as possible, as it will make receiving any winnings quicker and smoother.

Practical Example of a Sticky Bonus

A real example of a sticky bonus may look like the following:

• 200% bonus on deposits of up to £100, with a 35x wagering requirement on bonus only

In this example, a player may decide to deposit £50, leading to the casino giving them an additional £100 as a sticky bonus. The total that is playable is £150 as the two are combined. None of it can be withdrawn, as the £50 deposit becomes locked to the £100 credited by the casino.

The only way the £50 can be withdrawn is when the £100 has been wagered 35x. This would mean a player would have to wager at least £3,500 (£100 x 35) before being able to make one. This total must also be placed across qualifying games, such as slots.

Another example of a sticky bonus might look like the following:

• 200% bonus on deposits of up to £100, with a 35x wagering requirement on bonus and deposit

Keeping the example the same as above but adding the condition that the deposit also needs to have its wagering requirement met, the bonus becomes more expensive. It is worth noting that this form of a sticky bonus is very common in the UK.

Here, players would have to wager their deposit 35x, in addition to the bonus funds. So, the £50 would need to be wagered 35x (£50 x 35 = £1,750) on top of the £3,500 to meet the wagering requirements before a withdrawal can take place. This would mean a minimum of £5,250 would need to be wagered.

This can make it very difficult for players to clear the bonus, as they would need to spend significantly more. This can tempt players to exceed the maximum bet amount that is allowed, potentially forfeiting the bonus.

This is why the UKGC requires casinos to clearly state the terms of a bonus before it is claimed, ensuring players have transparency about what to expect before accepting any offer they see.

Pros & Cons for UK Players

Sticky bonuses can come with several advantages, hence their popularity with players in the UK. Still, they can also come with potential drawbacks and restrictions that may not make them incentivising for some depending on their playstyle.

Below, a table has been formulated to highlight the key pros and cons that can be found:

Pros		Cons
Better Bonuses	Sticky bonuses can come with bigger bonuses or higher match percentages compared to other offers.	Locked Deposit	The initial deposit becomes locked with the bonus; it cannot be withdrawn early and must meet wagering requirements.
Suitability	A sticky bonus can appeal to players who want a larger initial bankroll to play with. Sessions can be prolonged compared to other bonuses.	T&Cs Complicated	The T&Cs of a sticky bonus can be more complex and complicated to understand than other bonus offers.
Wagering Requirements	Conditions can match other bonuses, or they can be slightly lower, making them more appealing.	Time Pressure	Time conditions may not always be favourable. Short time limits may be imposed, which could encourage irresponsible gambling.

Best Practices for Maximising a Sticky Bonus

Players should adopt a strategy to maximise the effectiveness of a sticky bonus. Doing so can help them to improve win potential, continue to practice responsible gambling techniques, and stay safe with each session that is enjoyed.

Game Selection

Choosing the right game to play can make a huge difference in the effectiveness of a sticky bonus. Experienced players will often pick slots that have a medium volatility or those that contribute to the wagering requirements with high return to player (RTP) rates.

Games with these aspects can enhance the number or size of wins generated, with medium-volatility slots providing wins of varying sizes semi-frequently. Wins are typically bigger than low-volatility titles and can appear more often, although they are smaller than higher-volatility games. Still, they appear more regularly.

Budget Management

Playing with a budget is crucial. As funds are locked when using a sticky bonus, it can be easy for players to try and chase getting these back. This may involve placing more bets, which could entail spending more money.

Players should look to set deposit limits and even consider time constraints. These can help limit the amount of money that is spent, allowing safer gambling practices to remain being followed.

Reading Terms & Conditions

The best practice players can do to maximise the effectiveness of a sticky bonus is to read the terms and conditions. They give a complete overview of what to expect and how they should be used, ensuring there are no reasons for the bonus to be forfeited.

It can be easy to make certain errors when using a promotion because of the low limits or restrictions that are attached to them. Reading the terms and conditions can eliminate the chance of this happening.

Identifying Accepted Payment Methods

Some UK casinos do not always allow for every accepted payment method they offer to be eligible when claiming promotions like a sticky bonus. For instance, some e-wallets do not always qualify.

Additionally, there may be limits regarding a qualifying deposit. Players should ensure to check what the minimum and maximum limits are before claiming, as not meeting either of these could exclude them from the offer or make it void.

Common Pitfalls & How to Avoid Them

Sticky bonuses can be complex promotions offered by UK casinos, leading to various mistakes being made by players. Some of the most common pitfalls that some players can be caught out by include:

Max Bet Violations

A sticky bonus is often restricted in terms of the maximum bet that can be placed. A casino may set this at £5, as an example. Without reading the terms, some may eclipse this by placing a bet of greater value. By doing so, they will forfeit the bonus as they have not met the conditions that have been set.

Excluded Games

Game contributions play a huge role regarding the wagering requirements of a sticky bonus. A common pitfall experienced is when players play titles that do not contribute. When playing these games, they are not impacting the bonus, meaning they are not benefiting from the promotion and potentially wasting money.

Attempting Early Withdrawals

Sticky bonuses have a player’s deposit locked to the bonus part. Both parts will only be available to withdraw when the wagering requirement has been met. Players may not understand this and attempt to withdraw earlier, encountering issues. If they do, they risk violating the terms of the offer.

Time Expiry

A sticky bonus will come with time constraints. Some players may overlook this aspect and not realise they have to meet the requirements within a specified timeframe. Those who don’t risk forfeiting the promotion or not completing the playthrough as quickly as they potentially could.

Reading the Terms & Conditions

Players should always read the terms and conditions before claiming any type of bonus. They highlight what to expect and can help individuals avoid experiencing any of the common pitfalls that can be encountered.

Sticky Bonuses & the UK’s Responsible Gambling Framework

Responsible gambling is a significant focus of the UK gambling industry, as they aim to keep players as safe as possible and prevent harmful gambling from taking place. They do this by implementing various tools and resources to maximise player safety. This includes offering:

• Deposit Limits – A mandatory requirement for all UKGC-licensed casinos to offer.
• Reality Checks & Cool-Off Periods – Made available to players who may need help because of the addictive nature of gambling.
• Self-Exclusion – Allow players to protect themselves when they feel they need to by blocking access to an online casino for a specified time. This can be months or years.

Sticky bonuses are not exempt from these tools, allowing players to remain in control at all times and ensure they get the safest experiences.

With sticky bonuses tending to be higher in value compared to other bonuses, the possibility for players to chase big potential wins can increase, which is why these tools are paramount.

Responsible Gaming

The UKGC’s mission to promote responsible gambling is clear. They continue to place a huge emphasis on promoting safe gambling, with licensed online casinos required to follow this mandate and put in measures that encourage it.

Responsible gambling is all about making players understand the potential risks that the activity can bring, while outlining what they can do to increase their safety and stop them from engaging in harmful gambling activities. Online casinos are also required to do their bit to prevent this from happening.

This is achieved through the various measures that have been laid out by the UKGC. They include using tools like deposit limits, self-exclusion protocols, and offering time-out and cooling periods due to the addictive nature of the activity.

Online casinos are also required to offer access to independent charities and authorities for players who may need more assistance. These can come in the form of multiple organisations, all of which offer expert help. They include:

• GamStop
• GameCare
• GambleAware

Players can also improve their own safety by managing budgets, keeping an eye on their bankroll, understanding odds, never depositing more than they can afford to lose, practising discipline, and imposing self-limitations.

Conclusion – Is a Sticky Bonus Worth It?

When determining whether a sticky bonus is worth it, it can depend on the playstyle of a player. They can be a positive tool when used correctly, although there can be restrictions and risks with using one, especially when not all terms and conditions are fully understood.

A sticky bonus can be appealing to certain player types because they typically grant larger bonus sums and value. Still, they do tie the bonus and initial deposit together, with both unable to be withdrawn until the wagering requirements have been met. This can mean more money needs to be spent than on other bonuses.

Players who wish to use a sticky bonus must read all the terms and conditions of the promotion before claiming it. This will allow them to make an informed decision and ensure they are comfortable with what they are getting involved in. For some, more is not always the best approach.

Casual players may find that they are better suited to using a non-sticky bonus or an unlock bonus instead, especially if they want to withdraw any potential winnings early. Still, experienced players and high-rollers can enjoy what a sticky bonus brings, as they can be excellent for value and prolonging game sessions.

FAQs

How does a sticky bonus differ from other bonus types in the UK?

A sticky bonus will see both the deposit and bonus funds be combined in the player’s account total. Neither can be withdrawn early. A non-sticky bonus will see both remain parts separate, allowing winnings to be withdrawn without impacting the bonus early.

Why do some sticky bonuses apply wagering to both deposit and bonus funds?

Some sticky bonuses will lock a deposit and bonus funds together in a player’s account. Neither can be withdrawn until the wagering requirements have been met.

Can I withdraw partial funds halfway through meeting the wagering?

No, you must meet all wagering requirements before any funds can be withdrawn from the bonus. If you attempt to withdraw before meeting these, the promotion will be forfeited.

Do I have to verify my ID before playing with a sticky bonus at UK-licensed casinos?

No, but it can be advisable to do so. If you want to claim any potential winnings, you must complete the KYC checks as the UKGC requires this as a mandatory step.

What are the common time limits for finishing the wagering requirements on a sticky bonus?

The time limits imposed on sticky bonuses can vary. Most will be between 7 and 30 days, but it is best to check the specific terms and conditions of the offer to ensure they are met.

Are sticky bonuses limited to slots, or can I use them on live dealer and table games?

Game eligibility can depend on the casino. Slots are typically the only accepted type that contributes, but you may find smaller contributions available across other forms. Still, check the T&Cs to identify which titles are eligible and which are excluded.

Does every UK online casino offer sticky bonuses?

No, not every UK online casino will offer sticky bonuses. Many of the top-rated options do as these offers are found frequently, but they are not always available as widely as other options.

Are there typical maximum bet rules with sticky bonus funds?

Yes, maximum bet rules can apply to sticky bonuses. Depending on the casino and the offer provided, this can be of any value. Make sure to check beforehand, as placing a bet beyond the maximum can see the promotion become null and void.

How do I track my wagering progress to ensure I do not forfeit the bonus?

Most UK online casinos will provide a feature within your account that tracks your wagering progress. If not, contacting customer support can be a good step, as they should be able to help you with this.

Will a sticky bonus usually come with bigger sums than a non-sticky bonus?

A sticky bonus will typically provide bigger sums than most bonuses, including a non-sticky bonus. Still, this does not mean that it is always the right bonus to take. A non-sticky bonus does not have the two funds “stuck”, which may suit casual players better.

What happens if I fail to complete the wagering by the deadline?

The bonus will be forfeited if the wagering requirements are not completed within the time limits specified. When this happens, players will lose the funds that they were provided and any winnings that were obtained during the period.

Can I forfeit a sticky bonus once I have begun using it?

Yes, you can forfeit a sticky bonus once it is being used. Simply carry on playing responsibly and enjoying your session as normal, allowing for time to expire. Additionally, placing a bet of a greater value than the maximum allowed can void the bonus prematurely.

Do sticky bonuses come with a max win cap, and how do I find out?

Yes, sticky bonuses have a maximum win cap attached to them. This can be found out by reading the terms and conditions of the promotion, as UKGC-licensed casinos must display this clearly.

How does the UKGC ensure sticky bonus terms are fair and transparent?

The UKGC ensures the terms of sticky bonuses are fair and transparent by providing rules that online casinos must follow. They must display the terms in a clear and concise manner, while ensuring they are placed in a prominent position before and after the bonus has been claimed.

Can existing customers at a UK casino get sticky bonuses, or are they just for new sign-ups?

It can depend on the UK casino. Some will offer a sticky bonus as a welcome offer, whereas others will include them for existing players as a recurring promotion to incentivise them to continue playing with them.