Why Separation Matters
One of the most important rules in business finance is simple: keep your business money and personal money separate. Mixing them together creates problems that range from annoying to legally serious.
Tax Problems
When business and personal expenses are mixed, it becomes extremely difficult to identify which expenses are deductible. You either miss deductions (and pay too much tax) or accidentally claim personal expenses (which can trigger an audit).
Legal Protection
If you operate as a company or LLC, mixing funds can “pierce the corporate veil” — meaning you could lose the legal protection that separates your personal assets from your business liabilities.
Impossible Bookkeeping
Your accountant can’t do their job properly if every bank statement is a jumble of grocery runs, client dinners, Netflix, and software subscriptions. Sorting through mixed transactions wastes their time — and your money.
Common Mistakes to Avoid
Using One Bank Account for Everything
This is the number one mistake. When you use the same account for personal and business spending, every transaction needs to be manually reviewed and categorised. It’s tedious and error-prone.
Paying Business Expenses with Personal Cards
“I’ll sort it out later” is the most expensive phrase in bookkeeping. These transactions are easy to forget and hard to track down months later.
Not Paying Yourself Properly
Many business owners dip into business funds whenever they need cash. Instead, set up a regular owner’s draw or salary. It keeps things clean and makes your books reliable.
Lending Money Between Personal and Business Without Recording It
If you put personal money into your business (or take business money for personal use), record it properly. These are loans or owner’s draws — not just transfers to ignore.
Setting Up a Business Bank Account
If you haven’t already, open a dedicated business bank account. Here’s what to look for:
- Low or no monthly fees — many banks offer free business accounts for small businesses
- Online banking — for easy reconciliation with your bookkeeping software
- Integration with your tools — check if the bank connects with Fastbooks or your accounting platform
- A separate business credit or debit card — so you can pay for business expenses without reaching for your personal card
The Simple Rule
When in doubt, ask yourself: “Would this expense exist if my business didn’t exist?”
- Buying a laptop for work? Business expense.
- Buying groceries for dinner? Personal expense.
- Taking a client to lunch? Business expense.
- Taking your family to lunch? Personal expense.
If an expense is partly business and partly personal (like a phone you use for both), you can often claim the business portion. Keep a record of how you calculated the split.
Getting this right from the start saves you countless hours and headaches down the road. And it starts with one simple step: open that separate business bank account.