If you're moving abroad and you opened an ISA (Individual Savings Account) in the UK, you won't be able to put money into it after the tax year in which you have moved. Only Crown employees working overseas will be able to deposit money to their ISA while abroad.
You should notify your ISA provider as soon as you stop being a resident of the UK. You can still keep your ISA open and get tax relief on money and investments you hold in it. It is possible, however, that the ISA is not recognized as tax-exempt in your new country of residence, therefore we strongly advise you to get in touch with the local tax authorities for further details.
You'll be able to put money again (within the annual ISA allowance), once you come back and become a UK resident again.
Will I be able to use Trading 212's CFD and Invest account?
*If you have moved to the US, and you start paying taxes there, you won't be able to use our services due to the regulations of the Dodd-Frank Act and the FATCA Agreement.
In regards to the rest of the world, you'll be able to use our services and CFD/Invest platform as long as there aren't any local restrictions.