Cash Receipt Phone Number Registration and Deduction Check

If you receive cash receipts using your mobile phone number, you need to register it as an issuance method with Hometax. Without registration, your identity cannot be verified, so you cannot claim the income deduction. After registering, check that the receipts appear in your transaction history.

The deduction rates are based on the Restriction of Special Taxation Act effective September 18, 2026.

How to register your mobile phone number for cash receipts

Check your number in Hometax’s cash receipt issuance method management menu. A cash receipt is proof that records a transaction paid for in cash. Your mobile phone number identifies who made the transaction.

1. Log in to Hometax using an account in your name.
2. Under “Invoices, Receipts and Cards,” select “Cash Receipts (Employees and Consumers).”
3. Open the “Consumer Issuance Methods and Dedicated Cards” menu.
4. Select “Manage Mobile Phone Numbers/Cards for Cash Receipt Issuance.”
5. Check the number you actually use when paying, then register or update it.
6. Look up your cash receipt transaction history the next day.

The National Tax Service FAQ gives the following guidance on when you can view your history after registering.

If you sign up for Hometax and register an issuance method, you can check your cash receipt transaction history the next day.

This quote is from the National Tax Service document “If I do not sign up for Hometax, will I be unable to claim an income deduction during year-end tax settlement?” Do not assume that signing up also completes issuance method registration. It is more reliable to check your number directly on the issuance method management screen. National Tax Service registration guidance

If signing up for Hometax is difficult

You can also register an issuance method through the National Tax Service Tax Counseling Center’s automated phone system. The National Tax Service provides instructions for verification using a mobile phone in your name. Follow the phone prompts to register.

1. Call the National Tax Service Tax Counseling Center at 126.
2. Select 1 for the cash receipt automated service, then select 1 again.
3. Verify your identity and set a password for the automated service.
4. Register an issuance method, such as your mobile phone number.

Will cash receipts issued before registration be included?

Receipts issued using the same number before registration can also be included in your transaction history. Registering your number late does not mean you have to give up all your earlier receipts. After registering, check whether each transaction has been included. National Tax Service guidance on including transactions before registration

However, registering a number links you to transactions for which receipts have already been issued. It does not create receipts for transactions where none were issued. Nor does it automatically amend tax settlements for previous years.

Update your issuance method information when your number changes. If an earlier transaction does not appear, have the receipt from that time ready. Giving the National Tax Service the transaction date and approval number will help you make a more specific inquiry. Article 42 of the Regulations on the Use of Hometax

Comparing income deduction rates for cash receipts and credit cards

The income deduction rate for general cash receipt spending is 30%. General credit card spending is subject to a 15% rate. However, your annual eligible spending must exceed 25% of your total wages.

These rates are for general spending under the law effective September 18, 2026. Spending at traditional markets and on public transportation is calculated at separate rates. You cannot apply multiple payment-method deduction rates to the same expense. Article 126-2 of the Restriction of Special Taxation Act

An income deduction reduces the income on which tax is calculated. It does not mean you receive 30% of your cash receipt amount back in cash. The actual reduction in tax depends on factors such as your applicable tax rate and deduction limit.

How is the 25% of total wages threshold determined?

It is determined by adding together eligible card and cash receipt spending. Cash receipt spending is not compared with total wages on its own. Total wages also differ from the take-home pay deposited into your bank account.

• If eligible spending is at most 25% of your total wages, this deduction does not apply.
• If it exceeds the threshold, spending by payment method is entered into the statutory formula.
• The deduction limit for the relevant tax year applies to the calculated amount.

If you used multiple payment methods, do not multiply the entire amount above the threshold by 30%. The National Tax Service provides a formula by payment method. (Verified value: The annual deduction formula is general credit card spending × 15% + general cash receipt, debit card and prepaid card spending × 30% + applicable cultural and sports spending × 30% + traditional market spending × 40% + public transportation spending × 40%, minus the deduction related to the minimum spending threshold · Source: nts.go.kr · Checked 2026-10-20) Check the result using your actual spending on the year-end tax settlement calculation screen. National Tax Service guidance on the benefits of receiving cash receipts

Conditions for including family members’ spending

You can include spending by your spouse and direct ascendants and descendants if they meet the requirements. Direct ascendants and descendants include parents, grandparents, children and grandchildren. Your spouse’s direct ascendants are also included.

The income requirement for a family member is annual income of at most 1 million won. If they have only employment income, the limit is total annual wages of at most 5 million won. You must also check support requirements, such as whether you share a livelihood.

The age limit for the basic deduction does not apply to the income deduction for credit card and other spending. You may therefore miss eligible family spending if you look only at whether the family member qualifies for the basic deduction. Check the family relationship and income requirements separately. National Tax Service guidance on family deductions

If family members received receipts using their own numbers, check that each person has registered their issuance method. The process for an employee to view family members’ records is separate. You must also check their consent status for sharing records through the simplified year-end tax settlement service. National Tax Service guidance on viewing family members’ transaction histories

Comparing receipts for income deductions and business expense documentation

Distinguish between cash receipts for personal living expenses and business costs. Receipts for income deductions are used in employees’ year-end tax settlement records. Receipts for expense documentation provide proof of business-related costs.

Do not assume the receipt’s purpose just because you used a mobile phone number. If it was a business expense, check that the receipt is marked for expense documentation. If it was mistakenly issued for an income deduction, you can check Hometax’s change-of-purpose feature. National Tax Service guidance on cash receipt types and changing their purpose

Changing the purpose does not make VAT deductible for every business expense. The expense must be business-related and meet the requirements for an input VAT deduction. Do not also include an amount treated as a business cost in an employee’s deduction for consumer spending. National Tax Service guidance on benefits for businesses receiving cash receipts

If a transaction is missing, check issuance, attribution and deduction separately

If a transaction is missing from your history, checking issuance, its connection to you and its tax treatment separately can help narrow down the cause. The table below reorganizes National Tax Service guidance into a sequence of checks. First identify which stage has a problem.

Receipts issued without giving your number

You can separately register transactions issued without consumer information under the number designated by the National Tax Service. This happens when the seller issues a receipt without the consumer’s information. It is handled through a different menu from mobile phone number registration.

1. Check the approval number, issue date and transaction amount on the receipt.
2. Open Hometax’s “Cash Receipts (Employees and Consumers)” menu.
3. Select “Employee and Consumer Lookup/Change.”
4. Enter the transaction information under “Consumer Registration of Cash Receipts Issued Without Consumer Information.”

The National Tax Service provides guidance on transactions issued under the designated number 010-000-1234. If you see that number, check whether the receipt was issued without consumer information. If you do not have the information needed to register it, ask the seller for the receipt. National Tax Service instructions for registering receipts issued without consumer information

Common mistakes with cash receipt deductions

Even if a cash receipt appears in your history, its full amount may not qualify for an income deduction. You need to identify spending excluded from the deduction. In particular, check for expenses that overlap with other tax credits.

National and local taxes and apartment management fees are also excluded from this deduction. Amounts spent on gift certificates are likewise not included in eligible spending. You can check the rules on including family spending and excluded items in the National Tax Service’s simplified year-end tax settlement guidance. (Verified value: The income limit for including family spending is annual income of at most 1 million won, or total wages of at most 5 million won if the person has only employment income. Spending by a spouse and direct ascendants and descendants can be included; siblings and family members for whom another resident claims the basic deduction are excluded. National and local · Source: hometax.speedycdn.net · Checked 2026-10-20) National Tax Service simplified year-end tax settlement Q&A

Using a cash receipt card instead of a phone number

You can use a dedicated card or a Sontax mobile card instead of entering your phone number. A cash receipt card is an issuance method that identifies who made the transaction. Its purpose differs from that of a credit card used to pay.

You can apply for a physical consumer dedicated card through Hometax. The National Tax Service advises checking that the number on the card you receive matches the registered number. Apply for the card through the “Consumer Issuance Methods and Dedicated Cards” menu. National Tax Service guidance on applying for a dedicated card

Sontax provides a barcode linked to your cash receipt card number. Open the cash receipt mobile card in the app and show it. Scanning it at the store can replace entering your phone number. National Tax Service mobile card guidance