The two problems with commingling
1. Tax problem
The IRS treats commingling as a sign of sloppy records. Sloppy records don't disqualify deductions outright, but they shift the burden of proof to you in an audit. Normally, if you claim a $1,000 business meal, the IRS has to show it wasn't business. If you commingle, you have to show it was.
2. Legal problem (LLCs specifically)
An LLC creates a liability shield between your personal assets and your business. If you get sued over something your business did, only business assets are exposed.
But if you commingle — pay personal expenses from the business account, pay business expenses from the personal account, transfer funds without documentation — a court can "pierce the corporate veil." The protection disappears. Your personal assets become exposed.
This is called the alter ego doctrine. It's the single biggest reason solo LLCs lose their liability protection in court.
What "separation" actually means
- Business has its own checking account in the LLC's name (with the EIN)
- Business has its own credit card
- All business income goes into the business account
- All business expenses get paid from the business account or card
- To take money personally, you do a formal "owner's draw" — transfer from business to personal, recorded in your books
It's a workflow, not a one-time setup.
The easy path: free business banking
You don't need to pay for a business account. Options:
| Bank | Monthly fee | Notable |
|---|---|---|
| Novo | $0 | Online, integrates with QuickBooks and Stripe |
| Mercury | $0 | Good for tech/startup businesses |
| Relay | $0 | Multiple accounts (envelope budgeting) |
| Bluevine | $0 | Interest-bearing checking |
| Chase Business Complete | $15 (waivable) | Good branch access |
Setting it up (10 minutes if you have an EIN)
- Open a business checking account (free options above)
- Open a business credit card (Chase Ink, Amex Blue Business, Capital One Spark)
- Move all client payments to the new business account
- Update any recurring business charges to the business card
- Transfer your starting balance from personal to business as "owner contribution"
Owner's draws — how to do them cleanly
- One transfer per pay period (monthly is fine for solo)
- Label the transfer "Owner Draw" or "OD"
- Record in your books as reducing owner's equity, not as an expense
- Don't do draws for specific personal expenses — do one transfer, then pay personal expenses from personal account
Owner's draws are not deductible. They're just moving your own money. Don't make them show up on Schedule C.
The legitimate exceptions to strict separation
- Rare reimbursements. You accidentally paid a $50 software charge from personal. Reimburse yourself from business within 30 days. Document it.
- Starting expenses before the account existed. Track them, then reimburse from business after the account opens.
- Emergency. Business card declined, you paid from personal. Reimburse next day.
The standard is "occasional and documented," not "never."
If you've already been commingling
The fix is:
- Stop immediately. Open the business account. Move all new activity there.
- For the current year, retroactively categorize every transaction in your mixed account.
- Prior years: if you have a clean paper trail per transaction (receipts, invoices, bank statements), your deductions are defensible. If you don't, you probably overclaimed or underclaimed — either way, consider if amendment is worth it.
Don't try to "fix" old accounting by back-dating transfers. That's worse than the original commingling.
What the IRS looks for
- Large cash withdrawals from the business account
- Personal expenses paid from business (grocery stores, school tuition, hairdressers, personal medical)
- Round-number transfers with no apparent purpose
- Income going into personal accounts and not flowing to business
None of these is automatically disqualifying. All of them draw attention.
We flag commingling patterns in your CSV.
If you upload both your business and personal CSVs, we'll identify likely commingling and help you untangle it before tax time.