VUSA - Is there currency risk?

I was looking at investing in VUSA which is purchased in GBP. I thought as I was purchasing in GBP and the price is in GBP then there isn't currency risk? What's thrown me is that I came across the IGUS. So now I'm thinking that there is currency risk on the VUSA because the index it tracks is in USD. Is this right, or am I still missing the point?

You're missing the point. There is no extraordinary currency risk.

Consider this: you have a company operating in United States. The company's shares can be bought from New York Stock Exchange for United States dollars. For a US investor, there is no currency risk, right?

Then the company decides a dual listing: the shares will be listed in London Stock Exchange too for GBP. For a US investor, this investment adds currency risk that the investment in New York Stock Exchange doesn't have, right?

Both wrong!

Firstly, if you as a US investor buy shares of a US company, there is always the risk that dollar appreciates so one dollar will buy more euros, for example. Then the European competitors to this company will take full advantage of this, knowing that one dollar will buy more euros which is their home currency. So US investor investing in a US company sold in USD in an American stock exchange can actually have currency risk, after all! The competition makes this currency risk alive.

Secondly, dual listing does not change the nature of an investment at all. It is still the same company.

The same thing applies here: if you have numerous funds sold in different stock exchanges, all tracking the same index, their risk is exactly the same. It doesn't matter if the fund is sold in USD or in GBP or in EUR.

However, actively attempting to hedge against supposed "currency risk" can make some funds different. Don't invest in such a fund that does active currency risk hedging because it is not a trivial exercise to calculate the exact amount of currency risk in a particular investment. For example, if a European fund sold in EUR buys stocks sold in US stock exchanges for 1000 USD, the correct amount to hedge is not necessarily 1000 USD. It could very well be that one of the investments is Toyota shares, sold in US stock exchange. It could also very well be that some other investment is SolarEdge Technologies, an Israeli company, sold in US stock exchange.

The best bet to ensure you don't have any extraordinary currency risk in your portfolio is worldwide diversification. Then you have companies operating in all currencies. If some currency appreciates or depreciates, it could harm some of your investments, while benefiting other investments of yours.