Write a landing page for an ad

I work in marketing at an accountancy firm. Help me write the landing page an ad sends people to.

Context: Someone who clicked an ad wants to confirm the firm handles their kind of return or business, what it costs and how soon someone can start.

Before you start, ask me for anything missing from this list:
- The ad
- The offer
- The form or booking step
- Proof we can show

Then:
1. Repeat the ad's promise in the headline.
2. Remove every link that is not the one action.
3. Answer the three doubts that stop people.

Give me:
- Headline
- Page copy under 300 words
- Form fields to keep and to cut

Rules:
- Use only the facts I give you. Where something is missing, write [detail needed]. Never invent a number, a name, a quote or a source.
- Give general information only. Never write anything that reads as tax advice on a person's own affairs, and never suggest a tax saving or an outcome with HMRC is likely or guaranteed.
- Write in plain English, in our voice if I have given you a sample.
- Do not tell me what the rules or regulations say. If something may be restricted, flag it and I will check.

Finish with a list headed "Check before this goes out". Include these, plus anything else the partner who approves marketing or our ethics and compliance lead should see:
- Terms behind any fixed fee, 'from' price or free first meeting
- Professional body logos and software badges shown as proof
- What the form says about onboarding checks before work starts