# Separate Personal and Business Expenses on One Account

- Author: CheapBankConvert (https://cheapbankconvert.com)
- Published: 2026-10-17
- Category: Bookkeeping on a shoestring
- Canonical: https://cheapbankconvert.com/blog/separate-personal-and-business-expenses

> How to separate personal and business expenses when they share one bank account: tag the rows, total each side, and fix it going forward.
To separate personal and business expenses that went through one bank account, put every statement row into a spreadsheet, tag each one business, personal or split, and total each side. Only the business rows go into your books. Then stop the mixing at the source, with a separate account or a strict tagging habit.

## Why separating personal and business expenses matters at tax time

Separating personal and business expenses matters because only business costs are deductible, and you have to show which is which. A shared account blurs that line. If the IRS ever asks, a clean split with receipts is far easier to defend than a year of rows you sorted from memory.

The IRS is direct about this. [IRS Publication 583, on starting a business and keeping records](https://www.irs.gov/publications/p583), says you should keep your business account separate from your personal checking account. It also warns that proof of payment alone does not establish that you are entitled to a deduction. A card charge shows money left the account. It does not show the purchase was for the business.

Mixed accounts cause three practical problems:

- **Missed deductions.** Business costs buried among personal rows get overlooked when you total the year.
- **Overstated deductions.** Personal costs that slip into the business column inflate your expenses, which is the riskier error.
- **Slower help.** A bookkeeper or preparer has to ask about every unclear row, and you pay for that time.

None of this means a shared account is illegal for a sole proprietor. It means the sorting work falls on you, and it is easier done monthly than once a year.

## Tagging a shared account's rows as business, personal or split

Tagging a shared account means giving every statement row one of three labels: business, personal or split. A split row is a single charge that was partly for each, like a phone bill. Add a tag column beside the amount, work down the month in one pass, and leave a note on anything you had to think about.

Start by getting the rows into a sheet with date, description and amount columns. A bank CSV export is the quickest source. If you only have the PDF statement, a converter or careful typing gets you there.

Then set some rules before you start, so you tag consistently:

1. **Vendors that are always business**, such as your web host, a trade supplier or a coworking space, get tagged business without thinking.
2. **Vendors that are always personal**, such as the supermarket, streaming services and the gym, get tagged personal.
3. **Everything else gets a look.** Restaurants, fuel, electronics stores and online marketplaces could be either. Check the receipt or your calendar.
4. **Transfers to and from savings** are neither expense nor income. Tag them transfer and keep them out of both totals.

Add a fourth column for a short note. "Client lunch, J. Ruiz" or "printer ink, home office" takes seconds now and answers the question a preparer would otherwise ask in April.

Refunds need one more rule. A refund takes the tag of the purchase it reverses, so a returned business printer shows as a positive business row and reduces business expenses, not as income. Look up the original charge before you tag any refund, because the description on the refund row is often shorter or different.

Your statement file now carries a full picture of personal spending as well as business. If you store or send it, lock it first: [password protect an Excel bank statement file for free](/blog/password-protect-excel-bank-statement) covers the setting that actually encrypts the workbook.

## How do you handle an expense that is partly business and partly personal?

An expense that is partly business and partly personal gets split: work out the business share, record only that share as a business expense, and treat the rest as personal. IRS Publication 334 says to separate the personal part from the business part, and that the personal part is generally not deductible.

The [IRS Tax Guide for Small Business, Publication 334](https://www.irs.gov/publications/p334) states that rule for the general case. How you measure the business share depends on the expense:

- **Phone and internet.** Estimate the share of use that is for work, and keep a note of how you got there. A month of call logs or a usage estimate is better than a round guess.
- **A car used for both.** Business share is usually based on miles. A mileage log is the evidence that matters here.
- **A single purchase used for both**, such as a laptop, is split by how much it is used for work.

In the spreadsheet, a split row keeps its full amount in the amount column, so the account still balances. Add a business share column with the percentage, and a formula that multiplies the two. Your business total then sums that formula column, not the raw amount.

Be consistent from month to month. If the phone is 40% business in January, it should not be 80% in December without a reason you can explain.

## A worked tally of one mixed-account month

This worked example shows twelve rows from one month of a shared checking account, tagged and totalled. The vendors and amounts are made up. Money out is negative, money in is positive, and split rows carry a business share.

| Date | Description (example) | Amount | Tag | Business share | Business amount |
| --- | --- | --- | --- | --- | --- |
| 03-01 | Client payment, Design job | 1,800.00 | Business income | 100% | 1,800.00 |
| 03-02 | Supermarket | -96.40 | Personal | 0% | 0.00 |
| 03-04 | Web hosting | -24.00 | Business | 100% | -24.00 |
| 03-06 | Mobile phone bill | -70.00 | Split | 40% | -28.00 |
| 03-08 | Coffee shop | -6.50 | Personal | 0% | 0.00 |
| 03-11 | Office supply store | -58.20 | Business | 100% | -58.20 |
| 03-13 | Transfer to savings | -300.00 | Transfer | 0% | 0.00 |
| 03-15 | Restaurant, client lunch | -64.00 | Business | 100% | -64.00 |
| 03-18 | Streaming service | -15.99 | Personal | 0% | 0.00 |
| 03-21 | Fuel | -48.00 | Split | 30% | -14.40 |
| 03-25 | Design software | -22.99 | Business | 100% | -22.99 |
| 03-28 | Client payment, Logo job | 650.00 | Business income | 100% | 650.00 |

The business side for March comes to $2,450.00 of income and $211.59 of expenses, a business profit of $2,238.41. The personal side is $118.89 of spending plus the personal share of the phone and fuel. The $300 transfer appears on neither side.

Two checks keep the sort honest. First, the sum of the amount column should still equal the change in the bank balance for March, which proves no row was dropped. Second, scan the business rows for anything you could not explain to a stranger. If you cannot, it probably belongs on the personal side.

Under cash basis accounting, a common choice for sole proprietors, these rows are recorded in the month the money moved. [Cash basis accounting for small business](/blog/cash-basis-accounting-for-small-business) explains why that makes the bank statement such a convenient record.

## Owner draws and owner deposits on a mixed account

An owner draw is money the owner takes out of the business for personal use, and an owner deposit is personal money put into the business. Neither is an expense or income. On a shared account, personal spending is effectively a draw, so the personal tag already handles it. Deposits from your own savings need their own tag.

The common error is recording your own money coming in as sales. If you move $2,000 from personal savings to cover a slow month, that row is not income, and counting it as income means paying tax on your own money. Tag it owner deposit and leave it out of the income total.

The reverse matters too. A transfer from the shared account to your personal savings is not a business expense, however much it feels like pay. For a sole proprietor, business profit is what you are taxed on, and draws come out of profit, not before it. How to set up regular pay from the business, and how it shows in the books, is covered in [how to pay yourself from your business](/blog/how-to-pay-yourself-from-your-business).

## Can you keep business and personal expenses apart on one account going forward?

You can keep business and personal expenses apart on one account, but it takes a habit you repeat every week, and it never gets as clean as two accounts. The simpler fix is a second account used only for the business. Many banks offer basic accounts with no monthly fee if you meet a condition.

If you stay on one account for now, these habits reduce the sorting:

- **Use one card for business only.** Even on a shared checking account, a dedicated card puts most business spending on its own statement.
- **Pay business bills from one place.** Set every business subscription to bill that card.
- **Tag weekly, not yearly.** Ten minutes on a Sunday while you still remember the purchases.
- **Photograph receipts for anything ambiguous** the same day.

Whether a sole trader needs a dedicated business account, and what to look for in a cheap one, is the subject of [do I need a business bank account as a sole trader](/blog/do-i-need-a-business-bank-account).

If you are sorting a backlog of PDF statements, CheapBankConvert turns each one into a CSV or Excel file with a running balance column, priced per statement rather than per month. It is in early access, and the [CheapBankConvert homepage](/) shows the early prices.