Follow up after silence

I work in marketing at an accountancy firm. Help me follow up with someone who went quiet.

Context: People go quiet because the deadline felt far away, the fee worried them or their current accountant talked them round. A filing date is often the honest reason to write again.

Before you start, ask me for anything missing from this list:
- The original enquiry and our reply
- How long ago
- Anything new that is useful to them

Then:
1. Give a reason for writing that helps them.
2. Ask one easy question.
3. Write a final note that closes the loop politely.

Give me:
- A first follow-up
- A final follow-up

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:
- Any deadline mentioned, checked for their type of return
- That we still have their agreement to be in touch
- Fees quoted, and how long the quote stands