You can reply to a Reddit post for about six months. After that, Reddit archives it by default, which means new comments and votes are closed. Moderators can switch archiving off for their community, so some older threads stay open, and you can tell by whether a reply box appears.
Whether you should reply is a separate question. A late answer to a question that is still true can reach readers for months. A late answer that exists to mention your business reads as a bump and tends to be removed or ignored. This page sets out a short test for choosing, then explains why fresh threads are usually the better target.
What happens to old threads
Reddit announced in 2021 that posts older than six months are archived by default, and that moderators can turn this off in their community settings so comments and votes stay open. Archived posts remain readable. You just can't add to them. If you open an old thread and see no comment box, or a notice that the thread is archived, it's closed to you.
Even in a thread that is still open, the audience has moved on. Most of the people who commented have stopped checking, and the person who asked has probably decided. A reply may never be seen by the original poster, which matters if you hoped to start a conversation with them.
Why old threads still get found on Google
Reddit threads often show up in Google results for questions like "who do you recommend for..." and "is it worth..." because people trust real answers from other people. The thread that asked in 2025 may still be the page a buyer lands on next month. That is the argument for replying late: your answer is read by the next person who searches, not by the person who asked.
It's also why old threads are a trap. The Google visitor is rarely the poster and is not in the thread to ask you anything. A pitch placed there reaches few people and annoys the community. A genuinely useful answer reaches many and can keep working.
When replying to an older thread still helps
Run the thread through five checks. Reply only if the answer to all five is yes.
- The comment box is there. If the thread is archived, you can't reply, so stop.
- The question is still true. "How do I notarize a document on a Sunday?" is still true next year. "Best CRM in 2021" is not.
- You are adding something. Read the top answers. If yours repeats them, skip it. If you have a detail, a number or a correction they lack, go ahead.
- You would write it with no business reason. If the only point is to get your name in front of readers, don't.
- You can disclose. If the answer involves your business, say that you own it in the first sentence, and check that the community's rules allow it.
A worked example. Owen runs a mobile notary service. He searches Google for "notary on Sunday near me reddit" and finds a thread that ranks on the first page. It's 5 months old, it has 28 comments, and the newest was 3 days ago. The box is open, the question is evergreen, and the top answers say "ask your bank" and miss that many bank branches keep short weekend hours or none. He writes four sentences with that fact, and one line near the end that he is a mobile notary, for people who want someone to come to them. That reply passes all five checks. A second thread, 14 months old with the last comment 9 months back, would pass the first check only if moderators had turned archiving off, and the poster is long gone. He skips it.
When it looks like a bump or spam
A reply looks like a bump when it adds nothing but a mention. The usual signs: a reply to a thread that has been quiet for months, a first line that names your company, a link, wording that repeats a template you posted elsewhere, and an account whose recent history is only replies to old threads that mention the business. Moderators and readers notice patterns. Reddit's site-wide rules ban spam, and a string of identical late replies can look like it. Some communities also frown on answering very old posts at all, and a few will tell you in the rules.
Time-sensitive threads are the worst case. A reply to "need a plumber this weekend" posted six months ago is not help to anyone. Skip it.
Reply to fresh threads first
A fresh thread has an asker who is still deciding, a comment section being read, and a chance of a real exchange. That's where a reply is most likely to be seen and to lead to a conversation. Early replies do better than late ones, as the Reddit keyword alerts guide explains, and how to use Reddit search to find people ready to buy shows how to sort by new and filter to recent threads. A Reddit marketing strategy turns that into a four-week plan.
Conversations, the part of Rocketship that watches Reddit for you, searches for threads where someone asks for what you sell, ranks them by fit, and drafts a reply and a DM in your voice. It skips threads that are too old to take a comment when it can tell. Many of the threads it finds are recent, and some are older threads that still rank in Google. You read the draft, edit it, and post it yourself from your own account. Rocketship never posts, votes or messages for you. See how Conversations works.
Write replies that stay useful
If your answer might be read for months, write it for that reader. Put the date context in it ("as of this fall, prices in our area run..."). Avoid "this week" and "right now." Give the reason along with the recommendation, so it still makes sense when details change. Return and edit it if something changes. How to write a Reddit reply that does not read like an ad has the format, and recommendation threads when you sell the product covers the disclosure side.
How to check that a thread is still open
- Look at the post date. Anything under about five months is open unless a moderator locked it.
- Over six months: look for the comment box. If it isn't there, or you see an archived notice, you can't reply.
- Open or not, look at the date of the newest comment. If it is weeks old, the conversation is over.
- Read the community's rules in the sidebar before you write.
If the sidebar rules are unclear, a short message to the moderators costs a minute and can save a removal. Self-promotion rules for business owners shows how to ask.
Reddit threads are one source of buyers, and most buyers never post. Rocketship finds the buyers, emails them from your own Gmail, follows up, and books the meeting on its own. Plans that get you customers start at $24.99 a month (Launch), and every monthly plan starts with a 7-day free trial, card required.