Understand a tax notice and plan your reply

Explain the tax notice below in plain English and help me plan my reply, so that I know exactly what it says, what it asks me to do and by when, and can go to {{accountant}} with the right documents and questions. This is not tax advice: I am not asking whether the notice is right or what to argue, only for the notice to be made clear and my next steps organized.

The notice, copied exactly (I have removed ID and account numbers):
"""
{{notice_text}}
"""

The date on the notice, and the date and way I received it: {{dates}}
Today's date: {{today}}
What I believe about the matter, briefly: {{my_view}}
Records I have that relate to it: {{records}}

Use these numbered headings:
1. In brief: who sent it, which tax and period it covers, and what it says, in up to four sentences.
2. What they say changed or is owed: each item as the notice states it, with amounts, separating tax, penalties and interest where the notice does.
3. What they ask me to do: each action, quoted briefly.
4. Deadlines: every date or time limit, with the calendar date it falls on and the counting shown, flagged if it has passed or falls within 14 days of today.
5. The options the notice gives, such as paying, agreeing, disagreeing or asking for more time, described only as the notice describes them.
6. Documents to gather, each with why it relates to the notice.
7. Questions for my accountant, up to 8, most urgent first.
8. A next-steps checklist with dates.

For example, a deadline line might read: "'within 30 days of the date of this notice': dated [date], so due [date]; 9 days from today, flagged." That example shows the form only.

Keep it under 600 words, in plain language for someone who is not a tax professional.

Do not:
- Say whether the notice is correct, whether to agree or dispute it, or what penalties could follow beyond what the notice states.
- State tax rules, rates or rights from your own knowledge; if the notice refers to a rule, attribute it to the notice.
- Suggest ignoring the notice or waiting.

If the notice asks for payment by gift card, cryptocurrency or a transfer to a personal account, or gives only contact details I cannot check, say at the top that it may not be genuine and that I should confirm it through the tax authority's official website or phone number found independently, not the details in the letter. If a deadline can be read more than one way, give the date under each reading and add it to the questions rather than guessing which applies.