My Sister Taught Me Her "15-Day Rule," and It's Life-Changing

Rose Morrison

12 February 2025 at 0:30 pm·3-min read

<span> Credit: Carina Romano</span> <span class="copyright">Credit: Carina Romano</span> — Credit: Carina Romano Credit: Carina Romano

I’ve always looked up to my older sister, Mandy. She got good grades because of her diligence, remained healthy through disciplined eating habits and Pilates, and was always balanced in her personal and work life. But what I admire most is her intentionality.

As we got older, I realized Mandy embraced a minimalist lifestyle from a very young age, long before I ever read about it online. Her lifestyle is a far cry from my scattered thoughts, piles of belongings (that I am always sorting through), and overflowing closet of clothes. So, I decided to ask her how she does it all and fervently took notes as she taught me the simple and powerful practice that changed my life: the 15-day rule.

What Is the 15-Day Rule?

Have you ever gone to a store and left with more than you had on your shopping list? Or filled your online cart with 15-plus items that are on sale and such a “steal”? Much of this has to do with the immediacy of owning something rather than waiting and considering whether you truly need it.

Mandy doesn’t give in to impulse buying. She waits 15 days before whipping out her credit card instead. The downtime allows her to reflect on whether she needs or wants the item or if it’ll just take up more space. If she can’t shake her desire for it, she decides whether to follow through and will often use the one-in-one-out method to keep balance in her home.

The 15-day rule prevents her from mindless buying, which would otherwise lead to buyer’s remorse and additional clutter. As I look back, it’s no surprise I felt overwhelmed with my apartment. My kitchen was way too full, my fridge and pantry overstocked, and my desk covered with every unicorn, mermaid, and cat office supply I could find online.

How the 15-Day Rule Has Made a Difference in My Life

The 15-day rule completely changed my approach to shopping and ownership. Here’s how it’s helped me shift my mindset and make smarter purchasing decisions.

Shop Mindfully

I pause before buying items in my shopping cart and ask myself whether I really need them, if they’d bring me joy, and if I’d use them well. More often than not, the answer is no. It’s also amazing how, when you wait 15 days before purchasing something, you can separate needs from wants and realize you were just impulsive in the moment.

Minimize Clutter

I’ve become more intentional about what I bring into my home and assess whether there’s room for it. I’ve also adopted the 12-12-12 rule for decluttering. I find 12 items to discard, 12 to give away, and 12 to store in their proper place.

Recognize Spending Habits

I’m far more cognizant of how I spend money, using apps to track my finances and budget efficiently. Thanks to Mandy’s tip, I know where my money goes and how to prioritize purchases better.

Embrace Digital Organization

Mandy also uses apps to streamline to-do lists and inventory clothes, accessories, and beauty products. This approach has helped me plan purchases more effectively to avoid buying duplicates.

There’s no better time than the present to create a clutter-free space where you feel empowered and comfortable. Try the 15-day rule to help you eliminate excess through intentional purchases.

This M&S denim dress sold out within days, but has just been restocked