How Much Should You Set Aside for Tax? A Simple Guide for Small Business Owners

12 Aug How Much Should You Set Aside for Tax? A Simple Guide for Small Business Owners

Are you tired of the end-of-year tax scramble and wondering how much cash you actually need to tuck away?

For many small business owners, tax season can bring a familiar flutter of anxiety. Whether you are operating as a sole trader or running a limited company, watching money leave your business bank account to pay HMRC is never entirely painless. The secret to keeping your blood pressure low and your cash flow healthy isn't magic: it is consistency.

By setting aside a predictable percentage of your earnings every single month, you transform a terrifying annual or biannual bill into a routine business expense. But how do you know what percentage is right for you? In this guide, we will break down simple rules of thumb, explain the differences between Income Tax, National Insurance, Corporation Tax, and VAT, and share practical tips to make tax planning effortless.

What are the golden rules of thumb for tax savings?

How much of your hard-earned revenue should you realistically lock away each month?

While every business has unique margins and overheads, seasoned accountants and financial advisers typically rely on a few reliable rules of thumb. These figures are designed to give you a comfortable buffer so you are never caught short when HMRC comes knocking.

• For Sole Traders: Aim to set aside 25% to 30% of your net profits (or total self-employed earnings if you are just starting out). This generally covers both Income Tax and Class 2 and Class 4 National Insurance contributions.
• For Limited Companies: A standard rule of thumb is to place 20% to 25% of company profits into a dedicated tax savings account each month. This builds a robust reserve for your upcoming Corporation Tax liability.
• For VAT-Registered Businesses: Always separate the VAT portion of your sales immediately. If you charge 20% standard VAT, roughly one-sixth of every VAT-inclusive invoice belongs to HMRC, not your operating account.

These percentages are planning guidelines rather than rigid legal formulas. However, using them faithfully as a baseline will shield you from sudden cash-flow shocks. If you want a tailored breakdown suited to your exact income bracket, partnering with an experienced small business accountant can give you complete clarity.

Breaking down the main taxes: What are you actually saving for?

Do you know which taxes apply to your specific business structure?

Tax obligations depend heavily on whether you operate as a sole trader or through a limited company. Understanding what you are paying helps you calculate your set-aside rate with confidence.

1. Income Tax and National Insurance (Sole Traders)

As a sole trader, your business and personal finances are legally intertwined. You pay Income Tax and National Insurance on your net business profits: that is your total income minus your allowable business expenses.

• Everyone in the UK benefits from a Personal Allowance of £12,570, meaning profits up to this threshold are generally free from Income Tax.
• Profits above £12,570 fall into the basic-rate band (taxed at 20%), and higher thresholds enter higher-rate bands.
• National Insurance contributions (NICs) add another layer depending on your profit levels.

Because your overall tax rate climbs as your profits increase, setting aside around 30% of your profits ensures you cover both Income Tax and NICs comfortably.

2. Corporation Tax (Limited Companies)

If you run a limited company, the business is a separate legal entity. The company itself pays Corporation Tax on its taxable profits before you take your salary or dividends.

• Depending on your profit levels, UK Corporation Tax rates range from small profits rates up to main rates.
• Setting aside 20% to 25% of monthly company profits ensures your Corporation Tax bill is fully funded well before your payment deadline (which is typically nine months and one day after your accounting period ends).

3. VAT (Value Added Tax)

VAT is entirely separate from your income or corporation taxes. If your business taxable turnover exceeds the current UK VAT registration threshold (£85,000), you must register for VAT.

• You charge VAT on eligible sales, and you can usually reclaim VAT on eligible business purchases.
• The net difference is paid to HMRC quarterly.
• The golden rule: Never treat VAT receipts as turnover. Keep your VAT element ring-fenced from day one so it is untouched when your quarterly return is due.

Turnover versus profit: Why the distinction matters

Are you accidentally calculating your tax savings on total sales instead of net profit?

One of the most common mistakes business owners make is calculating tax percentages based on their gross turnover (total money coming into the bank account) rather than their net profit.

Tax is calculated on your profit: your revenue minus your deductible business expenses (such as software subscriptions, insurance, equipment, and professional fees).

Consider this quick scenario:

• Your business generates £60,000 in total sales over the year.
• You have £15,000 in allowable business expenses.
• Your taxable profit is £45,000.

If you mistakenly set aside 30% of your total turnover (£60,000), you would lock away £18,000. However, if your actual tax liability on £45,000 of profit is closer to £9,000 or £10,000, you have unnecessarily tied up thousands of pounds of working capital that could have been reinvested into your business growth.

Conversely, do not underestimate your tax by forgetting to deduct expenses or failing to track your invoices. Striking the right balance means reviewing your profit margins regularly.

Simple steps to build a bulletproof tax-saving habit

How can you take the stress out of tax payments once and for all?

Knowing the theory is helpful, but building practical daily habits is what protects your business. Here is a simple framework you can implement this week:

• Open a separate tax savings account: Never keep your tax money in your main operating account where it is easy to accidentally spend. Open a secondary savings account: ideally with a separate digital banking app: specifically for tax.
• Automate monthly transfers: Set up a recurring bank transfer that moves your chosen percentage (e.g., 20% or 30%) into your tax pot every time you get paid or at the end of every week. Treat this transfer like any other fixed bill.
• Use modern cloud accounting tools: Platforms like Xero make it remarkably easy to track your live income, expenses, and estimated tax liabilities in real time. When your bookkeeping is up to date, calculating your exact tax position takes minutes rather than days.
• Review your numbers quarterly: Don't wait until the end of the financial year to look at your accounts. Schedule a quick review every three months to check whether your set-aside percentage matches your actual earnings growth.

Partnering with professionals for total peace of mind

Would you like expert guidance to ensure your tax planning is spot-on?

Tax regulations, thresholds, and allowances can change, and every business has unique nuances that standard rules of thumb might not fully capture. Trying to guess your liabilities or worrying whether you have saved enough can drain your energy and distract you from what you do best: serving your clients and growing your enterprise.

At Harrison's Accountancy, we specialize in helping small business owners, sole traders, and limited company directors take complete control of their finances. As experienced Chartered Accountants and Xero Cloud Experts, we provide personalized, proactive advice that eliminates tax anxiety and keeps your cash flow optimized.

If you would like a clear, accurate assessment of how much you should be setting aside for your specific situation, get in touch with our friendly team today. Let's make tax season your easiest season yet!