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InvestEngine* is paying new customers up to £200 when they join and invest at least £100, but you're most likely to receive a much lower reward of between £20 and £24.

This is because the level of cashback you get is down to chance, with 75 per cent of people receiving the lowest amount.

There's a 5 per cent chance of scoring the top two tiers of cashback, paying between £75 and £200. 

This isn't the first time we've seen randomly generated rewards. IG periodically dishes out share bundles as an incentive to join, and the value of the shares you receive is random.

The type of deal we like most is cashback paid as a percentage of your investment – for example 1 per cent when you invest at least £10,000. This is straightforward and scales up the more you invest.

We examine InvestEngine's deal in more detail and explore how it stacks up with other options on the market right now.

> Sign up and get your welcome bonus at InvestEngine* 

How does InvestEngine's deal stack up?

The welcome cashback you can receive from InvestEngine* comes in different tiers, and you're not likely to receive the top amounts.

That being said, even a smaller bonus will boost your pot. 

If you're investing for your business there's more cashback available, but it's still randomly generated.

You need to stay invested for at least 12 months to keep the welcome bonus.  

Earlier this year InvestEngine ran an offer that paid up to £5,000 cashback, although you had to invest £2million to get that top amount. 

You would have bagged a £25 reward if you invested the minimum £5,000.

This was part of the flurry of deals that investment platforms introduce to win new customers at tax-year end. 

These offers usually dry up after April – and it's true that deals are currently thin on the ground.

It's worth considering InvestEngine's deal if you're looking for a new platform and want to give your portfolio a boost. 

It offers a stocks and shares Isa, self-invested personal pension (Sipp) and general investment account.

In our InvestEngine review, we said that the platform is good for investors seeking a straightforward and cost-effective way to invest in exchange-traded funds (ETFs) only.

The offer doesn't have a closing date and you must sign up using our link*. You should get the bonus within two business days.

What alternative deals are there? 

For an alternative, IG has consistently offered good deals and its latest one pays 5 per cent cashback when you invest at least £100 before 31 July, capped at £200. You'd need to invest £4,000 to hit the top amount. Find out more at IG*.

In our IG review, we said that the platform is suited to investors who want comprehensive trading tools. 

Beware that IG offers risky spread bets and contract for difference (CFD) trading. These are complex investments that are best avoided unless you understand them and are prepared to take the high risks involved.

IG itself says that 68 per cent of accounts lose money when trading these types of investments on the platform.

If you're searching for a new Sipp only, you could have a look at Interactive Investor's deal paying £200 cashback when you transfer or deposit a minimum of £20,000 into its pension. Find out more at Interactive Investor*.

This one has been extended a few times and is currently scheduled to end on 31 July.

Read our Interactive Investor review to find out how the platform performs.