# Hold Back Stock With an Inventory Buffer

> Keep a few units of every SKU off a marketplace so a sale that hasn't reached your inventory yet can't oversell, and read the buffered quantities Osello shows.

An inventory buffer holds a set number of units of every SKU back from the quantity Osello sends to a marketplace. With a buffer of 10, a SKU with 100 in stock is listed as 90. A SKU with 5 in stock is listed as 0. The buffer never sends a negative number.

## Why use a buffer

Osello mirrors the stock in your store (usually Shopify) out to your marketplaces, and it does that quickly — but not instantly. A sale somewhere Osello doesn't see right away — your own website, a marketplace you manage yourself, a wholesale order — takes a moment to reach your store's inventory, and a moment more to reach every marketplace. In that gap, two channels can both sell the last unit.

A buffer keeps those last few units off the marketplace. The marketplace can only sell what Osello tells it you have, so it can never sell into the units you're holding back. Pick a buffer that covers however many units might sell elsewhere in the time it takes a stock change to reach the marketplace — for most stores that's a handful of units, not dozens.

## Turn it on

The buffer is set per marketplace, so you can hold more back on a marketplace that oversells easily and nothing at all on another.

1. In the sidebar, open the marketplace and click **Settings**.
2. Open the **Offers** tab.
3. Switch on **Inventory Buffer**.
4. In **Buffer Quantity**, enter how many units of each SKU to hold back.
5. Click **Save**.

Osello immediately recalculates the marketplace's offers to show the buffered quantities, then sends them to the marketplace in the background — usually within a few minutes. You don't need to push offers by hand. Switching the buffer off, or changing its size, does the same.

## How the quantity is worked out

Every marketplace gets its own total per SKU, added up only from the locations you've enabled for it (see [choose which inventory locations count](/help/inventory-pricing/inventory-locations)). The buffer comes off that total, and the result is never below zero:

- **Marketplaces with a single inventory location** (Macy's, Nordstrom, Bloomingdale's, and most others) get the buffer subtracted once from each SKU's total.
- **Marketplaces that track stock per distribution center** (Target+) get the buffer subtracted from each distribution center separately, so every center keeps its own safety margin. With a buffer of 10 and a SKU that has 25 units in one center and 4 in another, Target+ is told 15 and 0.

The setting page tells you which of the two applies to the marketplace you're looking at.

The same buffer applies to every SKU on that marketplace. A SKU with less stock than the buffer is sent as 0 — a good sign that it's about to run out anyway.

## Reading buffered quantities in Osello

Once a buffer is on, every quantity Osello shows for that marketplace is the quantity the marketplace was told. When the buffer is the reason a SKU shows 0 — there is stock, but all of it is held back — a small superscript shows how many units are sitting behind that 0:

- 3 in stock with a buffer of 3 shows as **0**⁺³ — the marketplace sees 0, and 3 units are held back.
- 2 in stock with a buffer of 3 shows as **0**⁺² in yellow: stock is below the buffer, so it can no longer cover a sale elsewhere and the risk of overselling that SKU is higher.
- 12 in stock shows as **9** — hover over (or tap) the number to see the stock and the units held back.
- 0 in stock shows as a plain **0**: the buffer isn't what's keeping it at zero.

A listing's total inventory adds up its SKUs after the buffer; hover over it to see the stock behind the total. You'll see this on the marketplace's **Listings** table, each listing's page and variant page, and the marketplace's **Offers** page. Your product pages keep showing the real stock in your store — the buffer only changes what's sent to the marketplace, never your source data.

## Turn it off

Switch off **Inventory Buffer** on the same **Offers** tab and click **Save**. Osello re-sends the full quantities to the marketplace, and the superscripts disappear.

## Where to go next

- [How inventory syncs to your marketplaces](/help/inventory-pricing/how-inventory-syncs)
- [Choose which inventory locations count](/help/inventory-pricing/inventory-locations)
- [Offers: how price and stock reach a marketplace](/help/inventory-pricing/offers-price-and-inventory)
- [Why does my marketplace show 0 in stock?](/help/inventory-pricing/why-does-my-marketplace-show-0-in-stock)