How Much Inventory Should a Reseller Keep?

Why there is no universal number

The honest answer to a target listing count is: enough to keep your fast categories in stock, and no more. A number copied from someone else fails because three inputs differ from shop to shop — your capital, the median time your categories take to sell, and the hours you can put into prep and packing.

Someone working evenings cannot feed 300 listings; someone with 2,000 zł cannot fund them. The three limits below are computable from data you already have, if you keep records — the inventory spreadsheet template tracks cost, dates and payouts per item, which is all the limits need.

Limit 1: the share of your capital that may sit in stock

Pick a ceiling share and write it down — for example, no more than 40% of the bankroll in unsold stock at cost. With 5,000 zł set aside for resale, that means 2,000 zł can hang on the rail and 3,000 zł stays either working or free. Count stock at what you actually paid for it, cleaning and spare parts included; a ceiling checked against optimistic resale values stops working the first week you need it.

The ceiling exists so that one slow month cannot stop the business. When stock touches the ceiling, the next purchase comes only from what a sale pays back. Tighten it while testing a new category — 25% keeps mistakes affordable — and loosen it only after two months of data show the category earning its space.

Limit 3: depth per item vs breadth of listings

Depth is units of one item; breadth is how many distinct listings you run. Both need a cap. A workable depth rule: never deeper than two of a kind, and only in your best category — one of a kind anywhere you are still testing. Depth feels efficient and behaves like a bet that one size, one colour and one demand curve are all wrong at once.

Breadth has a platform ceiling too. OLX's listing limits (Annex 3, in force since 7 January 2026) cap free listings per category — 2 per private seller in smartphones, for example — and a limit renews 30 days after the last listing counted in it. On marketplaces with per-category quotas, going wide in one category runs into the cap and pushes you into paid listings, which changes the maths the breadth was based on.

Warning signs you are over-stocked

Ceilings fail quietly when nobody looks at them, so learn what over-stock looks like before it happens:

• Money: stock at cost sits above your capital ceiling, or the last batch was funded by anything other than sales.
• Days: a category's median days to sell has risen two periods in a row.
• Work: items bought more than two weeks ago are still unlisted — the prep backlog is the earliest warning.
• Space: storage costs money now, or the stock has spread beyond the shelf you planned for it.
• Exits: the same categories keep reaching the dead stock exit list two months running.

Two of these together mean stop buying in that category until the numbers return under the ceilings — not buy cheaper, not buy a little less: stop.

A weekly 10-minute inventory review

One short review a week keeps all three limits honest:

• Count the money: stock at cost against your capital ceiling.
• Count the days: each category's median against its days-to-sell ceiling.
• Clear the backlog: anything bought over two weeks ago gets listed this week or goes to the exit list.
• Check depth: more than two of a kind anywhere? That item gets no new buys until one sells.
• Decide the week's buys: which category, which ceiling each purchase fits under, before any money moves.

Example of the whole pass in one sitting: stock at cost reads 1,900 zł against a 2,000 zł ceiling — inside, but close. Knitwear's median is 22 days, coats 44, so coats are frozen. One jacket bought 19 days ago is still unlisted: it gets photographed on Tuesday or returns to the exit list. This week's budget is the 300 zł a sale paid back on Thursday, and it can only go to knitwear. Ten minutes, four decisions, no drift.

Related guides

• reseller cash flow
• organising reseller stock at home
• the days-to-sell metric