Prepare for a Self Assessment tax return without the mess

Help me prepare for a Self Assessment tax return.

Income types: [employment, self-employment, property, other]
Tax year: [year ending 5 April …]
Records I have: [invoices, bank CSV, expenses, none yet]
How I file: [GOV.UK, accountant, software]
What went wrong last year: [optional]

Ask me up to 3 short questions first if anything important is missing. Wait for my answers.

Then:
1. A document checklist for my income types.
2. A week-by-week prep plan before the deadline.
3. Common mistakes to avoid.
4. Questions for my accountant if I use one.
5. Point me to GOV.UK Self Assessment guidance for dates and how to file; do not invent deadlines.

Only use what I've told you, leave blanks for anything I haven't given, and don't invent facts, figures or products. This is help organising my own numbers and wording, not financial advice; point me to MoneyHelper, GOV.UK or Citizens Advice for guidance, and to a free regulated debt adviser if I'm struggling to pay. UK English.

For GOV.UK Self Assessment deadlines and records you must keep, use web search and name the page you used. If it doesn't search on its own, open View all tools and choose Search.

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