Apart from the Luno offer i have given info on to get £10 bitcoin with no deposit or purchase required for UK only, Coinbase does a great offer especially if you open up an account through Topcashback for UK users and make your 1st Trade where no minimum amount. I just traded Bitcoin at the time and bought £1 of Bitcoin which with fees cost a total of £1.99. Topcashback offer currently is £40 Cashback which i got around a few weeks later. There are also learn and earn tasks on Coinbase which can earn people between 20 and 30 pounds crypto equivalent. That can then be sold and converted into pounds and sold so that you could make around 20 pound plus profit after spending a total of £1.99 to do first trade of Bitcoin.
So many weeks later you will then get the £40 cashback from Topcashback which will be payable which people can withdraw to their bank account.
For me Coinbase if doing through Topcashback is my favourite other offer apart from Luno and on Coinbase they regularly have new learn and earn tasks to earn Free Cryptocurrency.
Here is info on Topcashback relating to cashback for Coinbase for UK users. Coinbase Black Friday Sales, Cashback Deals & Discount Codes | TopCashback