Hi all im new to this so still treading water, is there a interest rate on the 212 isa or does it just depend on performance?
Welcome to the Community, @Pacer 
You can earn interest on your uninvested cash in both types of investment accounts that we offer - ISA and Invest. The interest is paid daily, you can learn more on the topic here.
Hi @Pacer welcome.
Your comment suggests that you may not have a lot of experience (sorry if you have and these comments are thus naïve).
I obviously don’t know what research you did or what knowledge you have. However, there are different types of ISA and a cash ISA is like a bank deposit account that you can simply put money in and get interest but the interest will be tax free because its within an ISA. T212 is a share ISA so you put money in but can then invest in shares (which includes funds/trusts and other types of investment products). So if you put £10,000 into your share ISA you don’t have to invest any of it you could theoretically just leave the cash in the ISA but the intention is to invest it but you will probably not have all of your money invested into shares at any point in time. Thus any uninvested money will get interest. So, for example, if you put £10,000 in and bought £2000 of shares in 4 different companies you would still have £2000 that isn’t invested. That uninvested £2000 would get interest. Each of the 4 investments might go up or down and you can buy or sell them at any time.
Thanks for your help and yes im a newbie to this, so what interest would the uninvested cash in the isa attract?
T212 publish the interest rate information. This thread is probably a worthwhile read
Introducing daily interest on cash! - 
What’s new - Trading 212 Community