Income is still moving
When monthly income is uneven, seeing the latest figures together often gives a more grounded sense of the year.
Self Employed Tax Calculator UK
Use your income, expenses and payments already made to build a working figure for how much you may want to set aside for Self Assessment across the year.
Figures can shift as the year becomes clearer, so it helps to revisit the estimate when income, expenses or payments change.
When this estimate may be useful
This page is especially useful in the middle of the year, when you want a calmer sense of what you may need to keep aside.
You have already made payments
If tax has already been paid or covered through payments on account, the page helps fold that into the picture.
You want an earlier check-in
A quick review before the busy part of the tax year usually feels easier than leaving everything to the end.
Self-employed tax reserve estimate
Self-employed tax reserve estimate
Enter your figures for the selected tax year. This is a planning estimate for how much you may want to set aside for Self Assessment.
Choose the tax year this estimate applies to.
Income Tax bands vary by region. Scotland uses different bands.
Your total self-employed earnings before expenses, based on what you enter.
You usually cannot use the trading allowance and deduct actual expenses for the same income.
Expenses you believe may be deductible from your self-employed income.
Optional. Add other taxable income that may affect your overall Income Tax estimate, such as employment, pension or rental income.
Optional. Add tax already paid for this tax year if you want the reserve estimate to reflect it.
Optional. Payments already made towards this tax year can reduce the amount still to set aside.
Your estimate will appear here
Add your income, expenses and any payments already made. SelfYear will then show a planning estimate for your tax reserve, key dates and possible next checks.
How to use the estimate
The page brings together your self-employed profit, other taxable income and earlier payments to produce a working estimate for the selected tax year.
- Start with the best figures you have today, then refresh them as the year develops.
- Look at the set-aside figure together with your own records and cash flow, not in isolation.
- If something looks unexpectedly high or low, it is usually worth checking the inputs first.
- A fuller review becomes more useful once the numbers are settled and the year is further along.
What the planning estimate is trying to reflect
The aim is to reflect the main moving parts that tend to shape how much someone may want to set aside through the year.
Self-employed profit
The starting point is income minus allowable expenses, so the core figure stays close to the way many people track their year.
Income Tax and Class 4 NI
The page then brings in Income Tax and Class 4 National Insurance to shape a planning view.
Payments already made
Amounts already paid help reduce what still appears to be left in view for the rest of the year.
How to read the result
A useful way to read the result is as guidance to compare with what you already know from your records and the amount you have set aside so far.
- A higher set-aside figure can be a prompt to look again at how much of current income still feels available to spend.
- A lower figure can simply mean that more has already been covered through earlier payments or lower profit.
- The dates are useful points for review, especially if you want to avoid everything bunching up later.
- Unexpected results often become clearer once income, expenses and other taxable income are reviewed side by side.
Estimate FAQs
Short answers before you use the estimate or revisit it later in the year.
Can I use rough numbers?
Yes. Many people start with working figures and return later once records are tighter.
Why include other taxable income?
It can change the shape of the overall picture, so including it may give a more useful planning view.
How often should I revisit it?
It may be worth checking again when income changes, expenses build up, or payments on account have been made.
What if the result surprises me?
That can be a useful prompt to review the inputs first, then compare the working figure with your own reserve and records.
Keep this working figure connected to the rest of your year
Create a profile to keep tool results, records, reminders and next steps in one place as the year takes shape.