> ## Documentation Index
> Fetch the complete documentation index at: https://help.mathership.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Waste

> Record wasted ingredients and reduce inventory stock

# Waste

Waste is used to record ingredients that are no longer available for use.

Use waste when stock is lost, spoiled, damaged, thrown away, or otherwise removed from inventory without being sold or transferred.

<CardGroup cols={3}>
  <Card title="Record unusable stock" icon="trash">
    Post ingredients that were spoiled, damaged, expired, spilled, or otherwise lost.
  </Card>

  <Card title="Reduce inventory" icon="minus">
    Create negative inventory movements so stock balances stay accurate.
  </Card>

  <Card title="Track waste reasons" icon="clipboard-list">
    Add clear reasons to understand why stock was removed.
  </Card>
</CardGroup>

## What waste does

When waste is posted, Mathership creates a negative inventory movement.

| Action     | Ledger type | Stock effect                |
| ---------- | ----------- | --------------------------- |
| Post waste | `WASTE`     | Negative — stock is reduced |

Example:

| Ingredient | Storage unit    | Waste quantity | Stock effect |
| ---------- | --------------- | -------------: | -----------: |
| Tomatoes   | Kitchen Storage |           2 kg |        −2 kg |

## When to use waste

Use waste for:

* Spoiled ingredients
* Damaged goods
* Expired stock
* Preparation losses
* Dropped or unusable items
* Complimentary items given away
* Staff meals
* Customer returns
* Spillage
* Over-portioned ingredients
* Manual stock reduction that is not a sale, transfer, or count correction

## When not to use waste

Do not use waste for normal sales consumption.

| Situation                                | Use instead                 |
| ---------------------------------------- | --------------------------- |
| Stock used through sales                 | POS posting or recipe issue |
| Stock moved to another storage unit      | Transfers                   |
| Physical stock correction after counting | Stock counts                |
| Vendor delivery received into inventory  | Receive order               |

## How to open the waste sheet

Waste is posted from the storage unit detail page.

<Steps>
  <Step title="Open storage units">
    Go to **Manage** → **Storage Units**.
  </Step>

  <Step title="Open a storage unit">
    Select the storage unit where the waste happened.
  </Step>

  <Step title="Open Waste">
    Click **Waste** on the storage unit detail page.
  </Step>

  <Step title="Add waste lines">
    Select ingredients, quantities, units, and reasons.
  </Step>

  <Step title="Submit waste">
    Click **Submit waste** to post the waste movements.
  </Step>
</Steps>

## Adding waste lines

The waste sheet works the same way as the stock count and transfer sheets.

You add one ingredient line at a time, then submit all lines together.

Each line needs:

| Field         | Required       | Description                                |
| ------------- | -------------- | ------------------------------------------ |
| Ingredient    | Yes            | The ingredient being wasted                |
| Quantity      | Yes            | The amount to remove from stock            |
| Unit          | Yes            | Base unit or packaging unit                |
| Reason        | Yes            | The reason for the waste                   |
| Custom reason | Only for Other | Free-text explanation when using **Other** |

## Waste reasons

Reason is required for every waste line.

Choose from the built-in options or enter a custom reason.

| Reason          | When to use                                         |
| --------------- | --------------------------------------------------- |
| Spoiled         | Product spoiled before use                          |
| Expired         | Product passed expiry date                          |
| Damaged         | Packaging or product was damaged                    |
| Broken package  | Packaging broke, making the product unusable        |
| Quality issue   | Product was unusable due to quality problems        |
| Over-portioned  | More was prepared than needed and cannot be reused  |
| Spillage        | Product was spilled and lost                        |
| Complimentary   | Item was given to a guest at no charge              |
| Staff meal      | Used for staff consumption                          |
| Customer return | Returned by a customer and cannot be resold         |
| Other           | Any other reason — requires a free-text description |

When you select **Other**, a text input appears where you must enter a custom reason before the line can be added.

## Waste lines table

Once lines are added, they appear in the table above the add form.

| Column     | Description                                                                           |
| ---------- | ------------------------------------------------------------------------------------- |
| Ingredient | Ingredient name with current on-hand shown below                                      |
| Waste      | The quantity to be removed, shown with a negative sign and packaging breakdown format |
| Reason     | The selected reason shown as a pill badge                                             |
| Actions    | Edit and Delete buttons                                                               |

## Editing a line

Click the pencil icon on any line to edit it inline.

The row switches to edit mode showing:

* Quantity input
* Unit dropdown
* Numpad toggle
* Reason dropdown
* Custom reason input, if reason is **Other**

Click the save icon to confirm or **X** to cancel.

## Removing a line

Click the trash icon to remove a line.

This only removes it from the current waste session.

No stock has changed yet.

## Submitting waste

When all lines are ready, click **Submit waste** in the footer.

The footer shows the total count of lines, including any unsaved editor line that is ready to add.

When submitted, Mathership processes all lines as a bulk posting. All items are processed together in one request.

<Warning>
  Waste postings reduce inventory immediately after submission.
</Warning>

## Inventory value

Mathership calculates the inventory value of waste using the current weighted average cost of the ingredient.

**Waste value = waste quantity × weighted average cost**

The waste value is stored in the inventory ledger as a negative value.

## What happens in the ledger

Each waste line creates an inventory ledger entry.

| Field            | Value                                    |
| ---------------- | ---------------------------------------- |
| Transaction type | `WASTE`                                  |
| Quantity         | Negative                                 |
| Unit cost        | Weighted average cost at time of posting |
| Value            | Negative waste value                     |
| Storage unit     | The storage unit waste was posted to     |
| Ingredient       | The wasted ingredient                    |

This makes waste visible in ingredient history, storage unit reports, and inventory reports.

## Example

Current stock:

| Ingredient | Storage unit    | Current stock |
| ---------- | --------------- | ------------: |
| Tomatoes   | Kitchen Storage |         12 kg |

Waste posted:

| Ingredient | Quantity | Reason  |
| ---------- | -------: | ------- |
| Tomatoes   |     2 kg | Spoiled |

Result:

| Ingredient | Storage unit    | New stock |
| ---------- | --------------- | --------: |
| Tomatoes   | Kitchen Storage |     10 kg |

## Bulk waste example

Multiple ingredients can be wasted in one submission.

| Ingredient | Quantity | Reason  |
| ---------- | -------: | ------- |
| Tomatoes   |     2 kg | Spoiled |
| Lettuce    |     1 kg | Damaged |
| Cream      |    0.5 L | Expired |

All three lines are submitted together and processed in one ledger entry set.

## Entering quantities in packaging units

If an ingredient has packaging levels configured, you can enter the waste quantity in those units instead of the base unit.

For example, if butter has a packaging level of **1 Block = 250 g**:

| You enter | Unit  | System converts to |
| --------: | ----- | -----------------: |
|         2 | Block |              500 g |
|       500 | g     |              500 g |

When the entered unit differs from the base unit, the converted base quantity is shown below the input field in real time.

## Permissions

You can only post waste for companies and storage units you are allowed to access.

If you do not have access, Mathership returns an authorization error.

## Common errors

<AccordionGroup>
  <Accordion title="Ingredient not found">
    The selected ingredient does not exist or does not belong to the selected company.

    Check the ingredient and try again.
  </Accordion>

  <Accordion title="Storage unit not found">
    The selected storage unit does not exist or does not belong to the selected company.

    Check the storage unit and try again.
  </Accordion>

  <Accordion title="Reason is required">
    A reason must be selected for every line.

    If you chose **Other**, the custom reason text field must also be filled in before the line can be added.
  </Accordion>

  <Accordion title="Validation error">
    Required fields are missing or invalid.

    Check that ingredient, quantity, unit, and reason are all filled in correctly.

    Quantity must be greater than zero.
  </Accordion>

  <Accordion title="Authorization error">
    You do not have access to the selected company.

    Switch to the correct company or contact an administrator.
  </Accordion>
</AccordionGroup>

## Best practices

<CardGroup cols={2}>
  <Card title="Record waste immediately" icon="clock">
    Delayed waste entries make stock reports less accurate between the loss and the posting.
  </Card>

  <Card title="Add clear reasons" icon="clipboard-list">
    Specific reasons make it easier to identify recurring spoilage, over-portioning, or quality issues.
  </Card>

  <Card title="Use waste only for unusable stock" icon="triangle-exclamation">
    Do not use waste to correct stock counts or record sales. Use the correct feature for each situation.
  </Card>

  <Card title="Use packaging units" icon="boxes-stacked">
    If you count waste in boxes, blocks, or packages, select the packaging unit to reduce calculation errors.
  </Card>

  <Card title="Review waste regularly" icon="chart-line">
    Recurring waste for the same ingredients may indicate storage, portioning, or ordering problems.
  </Card>

  <Card title="Check the ledger" icon="list">
    Review waste entries in the ledger to confirm quantities, values, and storage units.
  </Card>
</CardGroup>

## Related pages

<CardGroup cols={2}>
  <Card title="Ingredients" icon="wheat-awn" href="/en/restaurants/inventory/ingredients">
    Learn how ingredients are tracked in inventory.
  </Card>

  <Card title="Storage Units" icon="warehouse" href="/en/restaurants/inventory/storage-units">
    Learn how inventory locations are managed.
  </Card>

  <Card title="Transfers" icon="right-left" href="/en/restaurants/inventory/transfers">
    Learn how to move stock between storage units.
  </Card>

  <Card title="Inventory Ledger" icon="list" href="/en/restaurants/inventory/ledger">
    Learn how stock movements are recorded.
  </Card>
</CardGroup>