# Source: https://getlago.com/docs/guide/plans/charges/spending-minimum.md

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

# Spending minimums

<Info>**Premium feature ✨**: only users with a premium license can define a charge spending minimum.
Please **[contact us](mailto:hello@getlago.com)** to get access to Lago Cloud and Lago Self-Hosted Premium.</Info>

Spending minimum concerns only usage-based charges which billing time is in arrears since these are always paid at the end of the billing period based on the amount of consumption that occurred. This feature allows you to define a spending minimum that a customer needs to commit to.

If your customer spends less than the committed amount, you will **charge a true-up fee equal to the difference between the commitment
and the actual usage**. Please note that this true-up fee is tied to the initial charge but will appear as a separate line item in an
invoice or in a credit note.

**Spending minimums and true-up fees are always prorated based on the number of days used in the subscription**. This ensures
fairness if your customer signs up at the end of the month, upgrades to a new plan, or terminates an ongoing subscription
before the end of the period.

In the example below, a customer is billed based on Monthly Tracked Users (MTU), with a standard pricing of \$0.010 per tracked users.
However, the customer is committed to a spending minimum of \$100. If the total consumption of MTUs for the period is \$50, a true-up fee
of \$50 will be charged.

To define a charge spending minimum:

<Tabs>
  <Tab title="Dashboard">
    1. Go to a **Plan**;
    2. Add a usage-based **charge**;
    3. Define a price model;
    4. Click the add a **spending minimum** button; and
    5. Define a spending minimum **amount**.
  </Tab>

  <Tab title="API">
    Use the `min_amount_cents` field on a charge:

    <CodeGroup>
      ```bash Spending minimum for a charge {24} theme={"dark"}
      LAGO_URL="https://api.getlago.com"
      API_KEY="__YOUR_API_KEY__"

      curl --location --request POST "$LAGO_URL/api/v1/plans" \
      --header "Authorization: Bearer $API_KEY" \
      --header 'Content-Type: application/json' \
      --data-raw '{
        "plan": {
          "name": "Premium",
          "code": "premium",
          "interval": "monthly",
          "description": "Premium plan for SMB companies",
          "amount_cents": 50000,
          "amount_currency": "USD",
          "trial_period": 0.0,
          "pay_in_advance": true,
          "bill_charges_monthly": true,
          "charges": [
            {
              "billable_metric_id": "1111_2222_3333_4444",
              "charge_model": "percentage",
              "pay_in_advance": false,
              "invoiceable": true,
              "min_amount_cents": 100,
              "properties": {
                "rate": "0.5",
                "fixed_amount": "1",
                "free_units_per_events": 3,
                "free_units_per_total_aggregation": null
              }
            }
          ]
        }
      }'
      ```
    </CodeGroup>
  </Tab>
</Tabs>