AM I able to bring forward an activation date

Perhaps best to have an online chat with the SMARTY customer support team, AdrianBi_216822. One of the advisers should be able to help you.

Contact support at https://smarty.co.uk/contact - scroll down to "Start a conversation".
The advisers work daily between 8am - 8pm.

AdrianBi_216822 Not sure if I understand this correctly.

When you activate a sim, it should be activated within a couple of hours at most.