Blog · 2026-09-17

LINE Auto-Reply Setup: Keyword Caps, Priority Rules and Four Official Numbers (2026)

The three built-in auto-reply behaviours, the documented caps of 51 keywords and 5 message bubbles, whether keyword matching is case-sensitive, and one feature that tutorials were still teaching in 2026 even though LINE announced its shutdown years ago.

A customer asks at eleven at night whether you are open tomorrow. You are asleep. By the time you reply in the morning, they have gone somewhere else. LINE auto-reply is what catches the customer while you are away.

This is not another walkthrough of the same setup screenshots. The focus is the hard rules written in the official manual that almost no tutorial mentions, because those rules decide whether your auto-replies are usable at all.

Three behaviours, and they are worth separating

Under Response settings in the console, the response mode is either Chatbot or Chat, with separate toggles for the greeting message for new friends and for auto-response messages. In operation there are only three behaviours.

The third is switching by business hours, and it is the one people overlook most. Fill in your opening hours under Response settings and you can route working hours to a live person and out-of-hours to automation. A single line after closing, something like "Message received. A member of the team will reply from 10am tomorrow", stops the customer feeling read and ignored.

What happens when both match at once? The official manual is explicit:

When a keyword condition is met, the keyword response takes priority.

Four official numbers that decide whether your auto-replies work

This is where this guide differs from every other LINE auto-reply tutorial. All four come from the LINE Official Account manual.

The second one deserves a note. Plenty of tutorials claim the keyword has to match exactly or nothing fires. That is half true. LINE explicitly ignores case and character width, so you do not need separate entries for LINE and line. But it is still string matching. If a customer asks "what time do you close" and the only keyword you set is "opening hours", nothing fires.

The fourth is the one that actually causes damage. Create three auto-response messages with no keyword and the system picks one at random when a message arrives. The one you intended as your greeting may never show up. Keep exactly one auto-response message with no keyword on the account.

Two more useful details: auto-response messages can be limited to a date or time range and assigned a time zone, and you can insert the user's display name, which previews as {Nickname}.

The feature tutorials still teach that LINE already shut down

Search for LINE auto-reply and you will find people teaching Smart chat's AI auto-response messages, explaining that it understands intent, so a customer asking "where is your company" is recognised as asking for the address.

The problem is the notice at the top of that very page in the manual:

The AI auto-response message feature is scheduled to be discontinued in May 2024. From 29 November 2023 you can go to the AI auto-response message settings and click Copy to move the content into the auto-response message feature.

The shutdown was announced more than two years ago, and Chinese-language tutorials updated in 2026 are still teaching it. Do not expect intent understanding from this built-in feature. If you want the bot to cope when a customer phrases things differently, the built-in tools cannot do it. That needs an external AI support agent.

Setting keywords that actually catch people

You only get 51 slots, so allocate them deliberately.

Configuration beats volume here. Focus on the three to five questions you get most. Opening hours, address, price, how to book, parking. Putting effort into those beats filling all 51 slots with words nobody types.

Put every phrasing of the same question in one reply. Your opening hours reply can carry all of these as keywords: opening hours, what time, how late, are you open, closed. That is what the 51 slots are actually for.

Turn keywords into Rich Menu buttons. This is the most effective way around the limits of string matching. The customer has no idea which words you registered, but they will tap a menu. Set that cell to send the text "opening hours" and the matching reply fires on tap. Auto-replies and the Rich Menu should be designed together, which is covered in the complete LINE Rich Menu guide.

Always leave a human exit. The last bubble of every reply should say clearly: "For help from a person, just send us a message. We reply weekdays 10:00 to 19:00." When the auto-reply cannot answer, admitting it and handing off beats forcing an unrelated answer.

Auto-reply templates you can edit and ship

Here are a few common scenarios. Swap what is in brackets for your own details and they are ready to use.

Welcome message for new friends

Welcome. You can check opening hours, book online and see this month's offers here. Just reply with a keyword. Type "book" and we will send you the booking link. For help from a person, just send us a message. We reply weekdays 10:00 to 19:00.

Outside business hours

We have your message. We are closed right now, and someone will reply from 10:00 tomorrow. For anything urgent, call (phone number). If you want to look something up now, use the menu below.

Price enquiry

(Service A) (price), (Service B) (price), including (what is covered). Full price list here: (link) If you are not sure which one fits, tell us your situation and someone will advise.

Booking

Book online here: (link). You can pick the date and time slot directly. To reschedule or cancel, just message us here.

Two principles when you write these. First, every reply gives the customer a next step. Do not answer and stop. Second, write the way you actually talk. Over-polished phrasing reads like a canned response.

When the built-in tools run out

The built-in auto-reply is free and good enough for a long time, but three situations hit a wall.

You cannot keep up with how customers phrase things. You add keywords every day and questions still slip through. That is not bad configuration. String matching has simply topped out.

You need different answers for different people. A member asking about price and a new visitor asking about price should not get the same answer. The built-in tool recognises words, not people.

You need to keep the support data. Who asked what, who is interested in what, none of it is recorded automatically. Tags in the console have to be applied one at a time by hand.

We built this into a product

Those three walls map to what our LINE OA platform does:

• Keyword auto-reply: keyword, event and condition triggers together, so it fires on behaviour and state as well as on strings
• AI support agent: RAG knowledge base plus an LLM. Feed it your FAQ, menu and service descriptions and it answers even when the customer rephrases. Answers come only from your knowledge base, and anything it cannot find goes to a human instead of getting invented
• CRM contact management: every interaction tags automatically, so support sees what this person tapped and which stage they are at before picking up
• Segmented push: use those tags to pick recipients and spend message fees on the right people
• 8-stage funnel tracking: from newly added to regular customer, with visible drop-off points

Three tiers, monthly fee in USDT, no lock-in:

The official account in your plan is registered under your own name, not parked under ours. Full specs are at LINE OA platform. If your customers come in through Telegram instead, Telegram Bot is the same approach.

FAQ

Can a personal LINE account do auto-replies? No. Auto-response messages are a LINE Official Account feature and personal accounts have no such setting. Add-ons that claim to auto-reply from a personal account usually want your login credentials, which is a serious risk and not worth it. If you want auto-replies, open an official account. The Light plan costs 0 per month.

Does LINE auto-reply cost anything? No. Auto-response messages, keyword responses, greeting messages for new friends and one-on-one chat messages are all on LINE's published list of free message types and do not consume your allowance. Outbound broadcasting is what costs money.

How many keywords can I set? LINE caps registrations at 51, and emoji cannot be used as keywords.

If an auto-response and a keyword response both match, which one sends? The keyword wins. The manual states that when a keyword condition is met, the keyword response takes priority.

How is an auto-reply bot different from the built-in auto-reply? The built-in version picks one message from a list you wrote in advance, matching on strings. An auto-reply bot runs on the Messaging API or a third-party platform and can handle intent, answer differently by who is asking, tag people automatically, and connect to your own systems. If the questions are predictable and the volume is low, use the built-in tool. If you are exhausted from adding keywords, it is time to change approach.

The rules and numbers in this article come from the LINE Official Account manual. LINE adjusts features and specs from time to time, so treat the current information in the console as authoritative.