A Practical Guide to Business Cash Receipts — Right at the Checkout

Editor's Note For those running a business, year-end and the new year can be hectic with bookkeeping and taxes.

Are you throwing away money you should be getting back in your daily routine? For example, when asked at the checkout, "Would you like a cash receipt?", many owners reflexively punch in their phone number. But this one small habit often means missing out on tens to hundreds of thousands of won in tax benefits a year. Cash receipts come in two kinds — "for income deduction" and "for expense proof" — and the one a business should get is the latter.

Today, we'll lay out step by step how to properly get a business cash receipt for expense proof, and how to fix it if you make a mistake!

ℹ️ 1. A one-number difference, a 10% loss — income-deduction vs. expense-proof

1. A one-number difference, a 10% loss Income-deduction vs. expense-proof — what's the difference?

Cash receipts split into two kinds by purpose. The number you enter and the benefit you get are completely different.

When a business gets a cash receipt with a phone number, the NTS classifies it as "personal consumption." As a result, it isn't recognized as a business expense, and a VAT refund becomes impossible.

Q. Concretely, how big is the loss? Suppose you buy a 1,100,000 won (VAT included) computer in cash.

✅ Entering your business number (for expense proof) • Expense recognized: 1,000,000 won • VAT refund: 100,000 won • Actual burden: 1,000,000 won

❌ Entering a phone number (for income deduction) • Expense recognized: 1,000,000 won (may be possible on a comprehensive income tax filing) • VAT refund: 0 won • Actual burden: 1,100,000 won

Just from pressing one wrong number, a 100,000 won difference arises. If your annual business-related cash spending is 10,000,000 won? You're simply giving up about 1,000,000 won in VAT.

2. A practical guide: do this at the checkout Basic procedure (3 steps) STEP 1. "Would you like a cash receipt?" → "Yes, for expense proof, please." STEP 2. Enter your 10-digit business registration number on the keypad. STEP 3. After getting the receipt, check the last digits of the business number. Tired of entering 10 digits every time? You can issue a "cash receipt card" in the NTS Hometax or Sontax app. How to issue it: Open the Hometax or Sontax app.

Select [Cash Receipts] → [Apply for a business-use cash receipt card]
Select [Apply for a physical card]
Carry the physical card in your wallet, or show the app card at the checkout. You won't need to memorize your business number, and you'll cut down on entry mistakes!

ℹ️ 3. Situation-by-situation checklist

3. Situation-by-situation checklist ⚠️ When you missed getting one ⚠️

Prepare the transaction receipt or supporting documents.
Use the Hometax → [Add expense-proof registration] menu.
Enter the transaction date, amount, and vendor info accurately. ※ Handle it as soon as possible (mind the deadline).

⚠️ Check regularly ⚠️

Check your issuance history on Hometax once a month or once a quarter.
Cross-check against your books to find omissions.
Review the split between personal consumption and business spending.
Organize your input-VAT deduction records before filing VAT.

⚠️ 4. Items not eligible for expense proof

4. Items not eligible for expense proof Not every cash expense is recognized for expense proof. The business relevance must be clear.

❌ Items not eligible for expense proof Personal shopping, clothing purchases Family meals, personal travel costs Hobby/leisure activity costs Personal consumption in general, unrelated to the business Even if issued under your business name, if the business purpose is unclear, it can become a problem in a tax audit. When in doubt, it's good to leave a business-related note on the receipt!

It's a good idea to consult an expert about expense documentation!

3 traps people often fall into

Trap 1. "As long as I get a cash receipt, I'm fine?"

Even if you got a cash receipt, if you got it for income deduction, you can't get a VAT refund. You must get it for expense proof.

Trap 2. "It's fine to pay with my personal card, right?"

Paying with a personal credit card may allow business-expense handling, but it's hard to get the input-VAT deduction. Use a corporate card or a card in your business name when possible, and for cash payments, always get a cash receipt for expense proof.

Trap 3. "I'll just sort it all out later at once, right?"

Changing a cash receipt's purpose or adding registrations has deadlines. Long after issuance, the change itself becomes impossible or complicated. Handle it the same day if possible, within a week at the latest.

Some find this part difficult, while others handle it themselves.

Let's look at when you need expert help and when you can do it yourself! Can do it yourself: ✅ when monthly transactions are few (10 or fewer) ✅ when expense items are simple and clear ✅ when you're comfortable with Hometax. Expert help recommended: when monthly transactions number in the dozens or more; when a year or more of missed receipts has piled up; when the split between business and personal spending is complex; when you need to prepare for a tax audit.

✅ Key takeaway: a business must always get cash receipts for expense proof

Just by entering your business registration number instead of the phone number you reflexively punch in, you can save tens to hundreds of thousands of won in taxes a year. One small habit, built up over one or two years, makes a real difference in running your business. If expense documentation is hard or you've missed a lot, rather than struggling alone, getting a tax expert's help is a good option too. What matters is managing cash receipts the right way, starting now. You can save costs this way — but how much more could you save by moving your office to a virtual office? Why not make a fresh start with CoworkCity, a virtual office available from around 10,000 won a month?

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