I size car seat confusion

[Smellybears]

Hello!
First baby due in January and the i size law has really confused me! There’s a car seat and isofix that I want which conforms to the current ECE R44/04 law but I don’t want to purchase it to find that in a few months I have to buy new car seat and isofix.
I’ve read that the laws will run along side each other but at point will the new law be compulsory and any precious car seats have to be replaced?
I know that I could just purchase an i size one now to avoid having to replace but just wanted people’s help please. It’s taken me a while to find the seat and isofix I actually want then I read about this new law and I’m confused!
Thank you! :)

[teaandbiscuitsforme]

AFAIK any seat that is for sale in the U.K. now is legal. You’re not going to have to change your seat until your baby has outgrown it so don’t worry!