Tax and bookkeeping for new businesses: avoid the surprise bill in year two

Tax and bookkeeping are the topics new business owners put off longest. Understandable, but expensive. Whoever reserves nothing in the first year often receives the bill for that year at the same moment as the first advance payment for the next. In the UK, for example, the self-employed generally pay two payments on account, each half of the previous year's bill, due by 31 January and 31 July (source: GOV.UK, October 2024). A few habits from day one prevent that double hit, wherever you are.

Income tax on profit or corporate tax?

Which tax you pay depends on your legal structure, not on the size of the business.

Which start-up costs are deductible?

The principle is similar in most systems: costs incurred wholly for the business reduce your taxable profit, while assets that last several years are written off over time through depreciation or capital allowances. Costs made before you start trading, such as market research, advice or a website, are often deductible too, under conditions. Two verified examples:

• United States: you can elect to deduct up to $5,000 of start-up costs and up to $5,000 of organisational costs, reduced by the amount by which those costs exceed $50,000; the rest is amortised (source: IRS, December 2024).
• United Kingdom: pre-trading expenditure incurred within seven years before the trade starts is allowed if it would have been deductible after the start, but not for capital expenditure (source: HMRC, August 2026).

Keep every receipt from the preparation phase, with a note of what it was for.

VAT, GST and sales tax: when must you register?

Value added tax works the same way almost everywhere. You charge it on your sales, deduct the tax on your business purchases and pay the difference. The money your customer pays as VAT was never yours. Countries set a turnover threshold above which registration is compulsory, and many offer small businesses an exemption below it. The trade-off is always the same: under an exemption you charge no VAT, but you cannot reclaim VAT on your costs either.

Thresholds checked in October 2026. They change, and some EU countries were still implementing the new SME scheme (source: European Commission, October 2026).

Check your country

• Threshold: the amount, which turnover counts, and whether the test looks back, forward or both.
• Exemption: is there a small business scheme, and what does it cost you in lost VAT deductions?
• Returns: monthly, quarterly or yearly, and whether a nil return is required.
• Cross-border sales: distance selling and digital services follow separate rules.

How to avoid a surprise tax bill

1. 01

   Move VAT out on receipt

   Each time a customer pays, transfer the VAT part to a separate savings account. Then the return is a formality, not a cash problem.

2. 02

   Reserve a fixed share of profit

   Work out with your marginal rates, or with your accountant, what share of profit goes to income tax and social contributions, and transfer it monthly.

3. 03

   Pay in advance where the system expects it

   In the US, individuals generally make quarterly estimated tax payments if they expect to owe $1,000 or more, and corporations at $500 (source: IRS, September 2026). Australian PAYG instalments are regular prepayments of tax on business and investment income (source: ATO, October 2023). Where advance payments are voluntary, they still spread the burden.

4. 04

   Keep your records up to date

   Book weekly, not at year end. With late bookkeeping you only find out when the return is due that the reserve was too small.

Example: what Yara sets aside

Yara is a freelance designer in a country with a VAT rate of 20%. In her first year she invoices €60,000 excluding VAT and has €9,000 of business costs excluding VAT, on which she paid €1,400 VAT.

If Yara saved nothing and her country uses advance payments of half the previous bill, the start of year two would bring her year-one bill of €15,300 plus a first advance of €7,650: €22,950 at once.

Fictitious Firmfocus example. The VAT rate and the 30% reserve are assumptions; your real rate depends on your country and income. The logic works in any currency.

Bookkeeping basics from day one

A business bank account keeps business and private money apart, which saves hours of sorting later. In most countries a sales invoice needs at least your name and address, the customer's details, a date, a sequential number, a description and the amount. In the EU your VAT identification number and the VAT charged must be on every invoice (source: Your Europe, May 2026). Then keep everything for as long as the law requires:

Small start vs larger start

Pitfalls

• Spending the VAT: it sits in your account but belongs to the tax authority.
• Forgetting social contributions: income tax alone understates what you owe as a self-employed person.
• Planning on old rules: thresholds, rates and allowances change, often every year.
• Missing a nil return: late filing can bring a penalty even when nothing is due.

The compliance calendar lists the returns and payment dates of the first year, and pay yourself shows how tax affects what you can take out. Back to the eight steps to start a business or Start a business.