"You only have until 5 April…"
This copy jumps straight to allowance limits and tax rules, without explaining to users what an ISA is or why it matters to them specifically. While its aim is to provide information-first urgency, there's too much explanation while users are still deciding if they even want an ISA.
Proposal:
Headline: "Save or invest with tax advantages"
Support copy: "Use this year's ISA allowance before it resets on 5 April. Save or invest up to £20,000."
The new suggested copy explains to users why ISA matters and motivates them to act with urgency.