Phone Won't Get a Signal at Home? Count From Your Sign-Up Date -- Call-Quality Cancellation Rules Split at 14 Days, Six Months and After
You switched to a new phone or a new carrier, and now the signal keeps dropping at home. Most people shrug and assume they are stuck because the contract is still running. But Korea's Consumer Dispute Resolution Standards set out when you can end a contract without a penalty because call quality is poor, and the rule has three tiers depending on how long ago you signed up: within 14 days, within six months, or later. What you do, and what you get back, differs at each tier. This post lays out the information published by the government's Easy Law portal and the Wiseuser telecom-user portal, step by step.

First, check that it is your main living area and not a handset fault
The rule applies at the user's main living area. Easy Law describes this as the address on your resident registration, the billing address, or your workplace. A dead spot on a trip or on a rare mountain visit may not count; the rule is aimed at poor signal where you stay every day, at home and at work.
Wiseuser gives this order. If call quality is poor in your main living area, first ask the handset maker for an A/S inspection to confirm the device itself is fine, and if it is, contact the carrier's customer center and ask them to test call quality in that area. If the problem started after you changed handsets, the cause may be the device, so skipping this step means the discussion goes back to square one the moment the carrier answers "it's your handset."
Within 14 days of signing up, you can cancel the contract outright
Annex 2, item 40 of the Consumer Dispute Resolution Standards recognizes cancellation (rescission) of the contract within 14 days of signing up when call quality in the main living area is poor. Easy Law explains rescission as undoing a validly formed contract retroactively. If the service contract and the handset sale were bundled, the handset and accessories are returned too. So in the first days after activation, keep the box and all the parts.

From day 15 to six months, you can terminate without a penalty and get half the base fee off
Even after day 15, if you are still within six months you can terminate the contract with no penalty and no discount-return charge, and the base fee for the month just before you apply is reduced by 50%. Unlike rescission, termination only ends the contract going forward, so charges already used are settled. If you were on a selected-contract discount, a discount-return charge for the remaining period would normally apply; here it is waived. Instead of terminating, switching plans may suit you better, so also see carriers must text you a cheaper plan every six months.
After six months, the clock is one month from your notice
After six months the method changes. If the carrier fails to fix the problem within one month of your notice that call quality is poor, you can terminate without a penalty or discount-return charge. At this stage, the record that you gave notice is the key. Do not just say it on the phone; use a method that leaves a date, such as a customer-center ticket number, a text message or an app inquiry, and save the screen. Wiseuser also notes that the carrier may ask for documents proving the grounds for a penalty waiver.
Right after porting your number, there is a separate 14-day withdrawal
If you moved your number from another carrier, there is one more rule. Article 6, paragraph 3 of the standards on implementing mobile number portability provides that within 14 days of porting, you can withdraw the port if call quality is a recognized reason. Easy Law gives the same guidance. Because the wording is "if recognized," keep the call-quality test record and its date together. After that period, the termination rules above apply.

"Occasional dropouts" and "service outage" are different standards
Separate from poor call quality, there is also a compensation standard for service suspension or outage. Under the same annex, item 40, you can receive compensation for an outage of 2 hours or more in a row, or 6 hours or more cumulatively in one month, and the minimum amount is 10 times the base fee and add-on charges for the time you had no service. The time is counted from the earlier of when you notified the carrier and when the carrier learned of the outage, and interruptions from natural disasters or from pre-announced line work are excluded. Easy Law explains that if your contract terms set their own standards, those apply first, and the Consumer Dispute Resolution Standards may apply where the terms are silent.
Two things to check after you terminate, and what to do if it stalls
After terminating, Easy Law advises contacting the customer center to confirm the carrier processed it properly and keeping a record of your request. You may also be owed unclaimed telecom refunds. You can look them up and apply on Smart Choice; they are paid only to the account holder's own bank account, and any unpaid balance is deducted. If you and the carrier disagree, telecom dispute mediation is available, as in when the carrier will not listen, you can move it to mediation. If the end of a contract discount is part of the question, the 25% plan discount ends when the contract does may help. If you use a budget (MVNO) plan, check your plan terms with the data safety option on MVNO plans.
The order of steps to take today
First, check your sign-up and activation dates to see whether you are within 14 days, within six months, or beyond. Second, confirm that the address with the problem is your main living area (resident registration address, billing address or workplace). Third, rule out a handset fault through A/S. Fourth, ask the carrier's customer center for a call-quality test and keep the ticket record. Fifth, request rescission or termination at the tier that fits, and ask whether proof documents are needed for the penalty waiver. How the rules apply to your own contract is for your terms and your carrier to confirm, and this post does not replace legal advice.
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