Set money aside for your tax bill so January isn't a shock

Help me set aside money for my Self Assessment tax bill.

How I trade: [sole trader, partnership]
Income so far this tax year: [amount, and months covered]
Expenses so far: [amount]
Other income: [e.g. a part-time job, rental income, or none]
Did I pay a payment on account last year: [yes, no, don't know]

First ask me up to 4 short questions. Wait for my answers.

Then:
1. Look up the current Income Tax and self-employed National Insurance rates on GOV.UK and name the pages.
2. A rough estimate of the year's bill using those rates and my figures, with the sums shown and each assumption marked.
3. A monthly amount to move into a separate tax pot, with a safety margin.
4. What payments on account are, in plain words, and whether they might apply to me, with the GOV.UK link.
5. A simple Google Sheets layout: month, income, expenses, set aside, running pot.
6. The key dates to put in my calendar.

This is a rough planning estimate, not tax advice. Tell me to check with HMRC or an accountant. Only use what I've told you, leave blanks for anything I haven't given, and don't invent facts or figures. UK English.

For current Income Tax and self-employed National Insurance rates on GOV.UK, 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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