What is the 30-day selling rule? This trick from the Minimalists will curb the sunk-cost fallacy and help you clear clutter with ease

We have all come across something in our home we should really declutter, but the initial cost of the item is making it impossible to let go. This is called the sunk-cost fallacy – an attachment to an item because of what we spent in the past, even if we now hate the item.

The idea of ‘sunk costs’ is one of the biggest roadblocks many of us face when decluttering our homes, resulting in items piling up that we feel guilty over, or are trying to sell online and failing.

That is where the 30-day selling rule comes in. Endorsed by The Minimalists, this simple rule helps you set realistic goals for selling your things and decluttering your home. Here’s why professional organizers love it, and how to decide if you should donate or sell to achieve your goals.

What is the 30-day selling rule?

The Minimalist’s 30-day selling rule dictates that you have 30 days to try and sell the item(s) in any way possible, gradually reducing the price the longer it remains in your hands. If you still have it at the end of the 30 days, you donate it. It is a great decluttering tip for those of us who struggle to be ruthless when decluttering.

Cara Palmer, professional home organizer and owner of Organize Every Room begins, ‘I find the 30-day selling rule to be an excellent framework for helping clients overcome the emotional barriers and decluttering roadblocks, particularly the sunk-cost fallacy. This approach effectively provides a structured timeline while acknowledging the item's potential monetary value.

‘The method's greatest strength lies in its clear endpoint. Many clients struggle with items they "might sell someday," which often results in storing things indefinitely. The 30-day deadline creates urgency and prevents decision paralysis. Additionally, the gradual price reduction strategy helps sellers understand that an item's value is determined by what buyers will pay, not what was originally spent.’

When to use the 30-day selling rule

Working out what to do with the items you are decluttering is the first step. Not everything is worth trying to sell.

Michelle Urban, professional home organizer and owner of The Organized House advises, ‘High-demand items – like luxury goods, high-end electronics, furniture, and collectibles – are usually worth the effort. But for everyday clothing, kitchen gadgets, or lower-value items, I often recommend skipping the hassle and donating them upfront. This avoids decision fatigue and keeps the decluttering process moving.

‘When working with clients, I often ask, “How much do you need to make on this for it to truly feel worth your time?” That simple question helps them rethink whether selling is actually the best move.’

Cara Palmer adds, ‘I wouldn't recommend this approach for seasonal items (better to wait for the appropriate season), family heirlooms or items with significant emotional value, or items worth less than $50 (the time investment often isn't worth the potential return).’

You can use a method such as the Post-It Note decluttering method to help assign items a final destination as you declutter, making it easier to identify sellable items at the end. Alternatively, use the minimalist 90/90 rule to cut back on the ‘just-in-case’ items cluttering up your home storage ideas.

How to sell items effectively online

There are, of course, some items you should never throw out when decluttering, but what do you actually do with the bits worth selling?

Cara Palmer says, ‘I would suggest a few refinements to make this method even more effective:

• Start with a market analysis: Before beginning the 30-day countdown, research comparable items to set a realistic initial price. This prevents wasting the first week or two with an unreasonable asking price.
• Establish price reduction intervals: I recommend planning three price drops – on day 10, day 20, and day 25. This systematic approach prevents emotional pricing decisions and ensures steady progress toward sale or donation.
• Choose the right selling platforms: Different items perform better on different platforms. For example, furniture often sells well on Facebook Marketplace and OfferUp, while collectibles might do better on eBay or specialized forums.
• Stick to the timeline: The key to success with this method is commitment to the timeline. I advise clients to mark the donation date on their calendars and arrange pickup in advance. This creates accountability and prevents last-minute hesitation.’

FAQs

What are the best online-selling platforms?

There are several online selling platforms you can turn to, depending on the items you are trying to sell. For local sales of furniture and clothing, Facebook Marketplace or Craigslist are good options. Clothes are best on platforms like eBay, Vinted, Poshmark, and Depop, and it's worth noting eBay is also good for rarer items or collectibles. Vestiaire Collective is perfect for luxury fashion goods, with authentication available to give buyers peace of mind and increase the likelihood of a high-ticket sale.

This is not the first lesson I have learned from The Minimalists, and there are so many decluttering methods you can try to help whittle down your stuff. Remember, to set yourself up for a successful decluttering session, you should not go into the process actively hunting for items to make money.

Your goal should be to make space and make your home easier to manage. Anything you get rid of or manage to see is just a bonus. This way, you are far less likely to experience declutter regret.