Most reselling mistakes I see are not buying mistakes. They are timing mistakes. Buying the wrong lot costs you once; restocking at the wrong moment costs you twice - once in dead cash, once in a dead listing. After enough of both, I narrowed my whole restock decision down to one number and one habit. This is the full method.

Sell-Through Rate: The Only Number That Matters

Sell-through is dead simple: units sold per week, on that SKU, in your store. If you sold 12 units of a night light last week and 10 the week before, your sell-through is 11 a week. Everything else - the excitement, the "it's trending" feeling, the supplier's urgency - is noise. The restock question is arithmetic: how many weeks of stock do I have left, and how many weeks until a new order is in my hands? Reorder when the second number gets close to the first. Not before, not after.

Divide your remaining units by your weekly rate and you get weeks of cover. Weeks of cover is the number I check every Monday in ten minutes. Below four weeks, the SKU goes on the watch list. Below two, the order goes out. It is boring and it works.

Lead Time Changes Everything

The reorder trigger is useless until you know your true lead time - and most resellers guess it short. A domestic FBA lot that shows in-stock today might ship this week and sell out mid-transit; a popular clearance SKU can vanish before your payment clears. My rule: lead time equals shipping days plus one week of safety, because clearance inventory does not restock. When a lot is gone, it is gone forever - which is why the watch-list habit matters more here than in conventional wholesale.

Reading Stock Counts Before You Reorder

This is where clearance sourcing differs from normal wholesale: the supplier's stock count is part of your decision, not background information. When I buy, I read the count on the product page and work out what it means for my reorder window. A lot like the pet grooming brush with 553 pieces in stock at $2.10 gives everyone room - even if half sells this month, there is depth for a second order behind it. Compare that to a lot showing 40-70 pieces, like the pet water fountain at 73 units: the correct move there is to buy your full run at once, because there will be no restock to time. Deep stock rewards patience; thin stock punishes it.

The same logic scales with MOQ. A 1,000-plus-piece lot like the pruning shears at 2.20 lets me stage orders across a season. A 20-MOQ lot like the RGB night light at $3.30 is cheap enough to buy two MOQs upfront and skip the reorder decision entirely.

The Two-Week Rule I Actually Use

Here is the habit in practice. Every Monday: pull units sold last week per SKU, divide remaining stock, flag anything under four weeks of cover. Every order day: for each flagged SKU, decide buy-or-let-die. Letting die is a legitimate answer - some SKUs deserve a graceful end, especially seasonal ones. A Christmas light with three weeks of cover in December gets bought; the same light with three weeks of cover in October gets replaced with something evergreen. The rule is mechanical precisely so that a busy week cannot talk me into emotional decisions.

When NOT to Restock

Three stop signs. First, falling sell-through: if weekly sales dropped 30% two weeks running, something changed - competition, price, reviews - and restocking just refills the problem. Second, margin squeeze: if the platform raised fees or the category got flooded and your landed margin dropped below your floor, the reorder is how you lose money politely. Third, aging stock elsewhere: if you still have 60% of a related SKU on the shelf, the cash is better spent moving that. Cutting a slow line cleanly is its own skill - there is a whole piece on running the routine around a day job that pairs with this system.

What This Looks Like in Real Numbers

A recent example from my own books. A $2.10 brush SKU selling 9 a week, 24 on hand: 2.7 weeks of cover. Order trigger fired - but I checked the supplier page first, saw 553 pieces of depth, and placed a 100-unit order instead of 50, because the deep stock removed the sell-out risk and the extra $105 bought me five quiet weeks of not thinking about it. That is the whole game: the spreadsheet tells you when, the supplier's stock count tells you how much.

Building the Monday Review Habit

The system only works if the review actually happens, so make it stupid-proof. Same time every Monday, same spreadsheet, four columns, ten minutes. I run mine with coffee before the workday starts, because review sessions scheduled "sometime this week" do not survive a busy week. The spreadsheet does not need to be pretty - it needs to exist long enough for patterns to surface. After a month you will notice which categories consistently under-run their cover estimates, which listing photos quietly went stale, and which SKUs sell in bursts that your weekly average hides. That is when the habit starts paying beyond restock timing. Pair the Monday review with a monthly margin audit and you have the entire back office of a serious one-person operation. If the whole routine feels heavy alongside a day job, the part-time selling routine shows how to compress it further, and the market news feed is worth two of those ten minutes for demand signals.

A last word on where the stock itself comes from. Every trigger decision above assumes the lot is actually available when you go to reorder - and with clearance sourcing, that assumption fails often, which is exactly why the watch list exists. When a flagged SKU's lot is still live, ordering takes minutes through the How to Order page. When it shows Sold Out, the decision makes itself and the budget rolls to the next watch-list item. Keep the browse session short and scheduled rather than mood-driven; the full operational archive sits on the seller guide hub if you prefer to batch your reading. Discipline at the reorder moment is where this system either compounds or quietly collapses.

How do I track sell-through without software?
A spreadsheet with four columns - SKU, units left, sold last week, weeks of cover - is enough. Update it once a week; the ten-minute version beats any dashboard you will abandon.

What weeks-of-cover threshold should I use?
Four weeks as the watch trigger and two weeks as the order trigger fits most domestic FBA sourcing. Stretch the trigger earlier for anything seasonal.

What if the SKU sells out before my reorder?
With clearance stock this happens and cannot be undone - treat it as tuition. Next time, the thin stock count on the supplier page is your signal to buy the full run at once.

Should I reorder at the same quantity?
Only if the margin and sell-through both held. Rising sell-through with stable margin justifies stepping up 50%; anything else, repeat the proven size.