If a shop issued a Korean cash receipt to a phone number or card but the transaction is missing from your Hometax history, first ask which identifier was entered at checkout. The National Tax Service’s missing-history answer explains that a receipt issued to an unregistered phone or card identifier may not attach to the user’s account. Registering the identifier is a different task from asking a merchant to issue a receipt that was never created.
Identify the missing link before changing an account
Keep the merchant slip or message showing the date, amount and any approval number. If it shows the phone or cash-receipt card used, compare that identifier with the consumer issuance methods registered in Hometax or the official Sontax mobile management screen. The screen explicitly has separate phone-number and card entries. A new phone number does not automatically make older receipts visible under the account.
The live Sontax screen says a phone number must be in the holder’s own name and passes carrier identity verification before registration. If you cannot pass that step, repeating it with a borrowed number is not a reliable recovery plan. The NTS answer also names its 126-1-1 phone route for issuance-method registration, but that route may still require identity checks. Ask NTS which assisted method is available for your actual identity and receipt instead of assuming a tourist SIM or someone else’s line will work.
Register, then check the record again
Use the current Hometax consumer cash-receipt issuance-method menu or the Sontax registration screen to register the same identifier used when the merchant issued the receipt. The NTS answer says linked history can be queried from the next day after registration. Save the registration confirmation, then search by the transaction date and amount. Do not treat an empty same-day result as proof of failure, and do not promise that every historic purchase will appear: the FAQ is from 2020 and account-specific conditions were not tested here.
If the slip instead says the merchant issued a voluntary receipt under the NTS designated number, the Sontax voluntary-receipt screen is a different route. It says registration is available from the day after issuance and requests the approval number, transaction date and amount; do not enter a guess. If there is no receipt or approval evidence at all, contact the merchant about issuance and ask NTS about the applicable reporting route. Registering a phone number cannot create a transaction the merchant never issued.
This check is about record attribution, not whether a purchase qualifies for a deduction or whether a tax return changes. Those questions belong to the NTS. Preserve the original receipt, any registration confirmation and the Hometax result when you ask for help; avoid sending a full phone or identity number in an open message.
NTS FAQ and current Sontax public screens checked September 29, 2026 KST. No Hometax account, carrier verification, receipt registration or tax result was tested.