Manage cost

This guide describes how to set a cost limit on your Pay-As-You-Go Plan instance. You can also manage cost by minimizing a workload's quantum time, and setting a maximum execution time on your workloads.

The cost limit refers to the total cost of all workloads run with this instance since it was created, and it will always be greater than or equal to the total cost. After the instance reaches the specified number of total seconds, no further workloads can be run and no more cost is incurred.

Note

The cost limit is always specified in US dollars (USD), then converted to runtime seconds. However, for monthly billing purposes, you are charged in your local currency, specified on your IBM Cloud® account. Because currency exchange rates can fluctuate, the cost for X runtime seconds might be different when initially calculated in USD than when you’re actually charged in your local currency. As a result, if your local currency is not USD, the total amount charged for the number of seconds specified in this field could vary from the dollar amount you specify.

Set or change a cost limit

There are several ways to set or change a limit on how much is spent:

IBM Quantum Platform: Open the Instances table. Find the instance you want to limit, click the overflow menu at the end of the row, and then click Edit details. Set the total cost limit or the usage limit, then click Save changes.

Note
You can also set the cost or usage limit when creating a new instance under the Pay-As-You-Go Plan. When you select the Pay-As-You-Go tile, a field appears with the label "Total cost limit (Optional)". You can enter a total cost limit in this field.

API: Set the instance limit in seconds.

PUT /v1/instances/configuration "instance_limit":<seconds>

IBM Cloud CLI: For instructions to use the CLI, refer to Getting started with the IBM Cloud CLI.

   ibmcloud resource service-instance-update <instance_CRN>
   -p '{"instance_limit_seconds":"<seconds>"}'

View the cost limit

There are several ways to view the current cost limit:

IBM Quantum Platform: The Max cost limit is shown on the Pay-As-You-Go tab of the Instances table.
API:
```
GET /v1/instances/configuration
```
See the REST API documentation.
IBM Cloud CLI: For instructions to use the CLI, refer to Getting started with the IBM Cloud CLI.
```
ibmcloud resource service-instance-update <instance_CRN> -p
'{"instance_limit_seconds":null}'
```

Remove a cost limit

You can remove the cost limit in several ways:

IBM Quantum Platform: Open the Instances table. Find the instance you want to update, click the overflow menu at the end of the row, and then click Edit details. Delete the total cost limit or the usage, then click Save changes.

API: Set the instance limit to null.

PUT /v1/instances/configuration "instance_limit":null

IBM Cloud CLI: For instructions to use the CLI, refer to Getting started with the IBM Cloud CLI.
```
ibmcloud resource service-instance-update <instance_CRN> -p
'{"instance_limit_seconds":null}'
```

What happens when the cost limit is reached

When the instance’s cost limit is reached, the currently running job is stopped. Its status is set to Canceled with a reason of Ran too long. Any available partial results are kept.

No further jobs can be submitted by using this instance until the cost limit is increased.

How to see what you’re being charged

You will receive a monthly invoice that provides details about your resource charges. You can check how much has been spent at any time on the IBM Cloud Billing and usage page.

Additionally, you can determine cost per instance or per job at any time.

View usage

View the instance's usage on the Analytics page.

View instance cost

To determine how much has been billed to an instance during the current billing cycle, from the Instances page, click the instance to open its details page.

These are the fields relevant to cost:

Billing cycle usage: The amount of quantum time used by this instance during the current billing cycle. Quantum time is the duration a QPU is committed to fulfilling a user request.
Billing cycle cost: The total cost of running jobs during the current billing cycle.
Total usage: The amount of quantum time used by this instance since it was created.
Total cost: The total cost of running jobs on this instance since it was created. Only administrators can set this value.

You can view your billing cycle on the Billing and usage page.

View job cost

To determine how much has been billed to each job associated with an instance, from the Instances page, click the instance to open its details page. Next, on the left side, click Jobs.

These are the columns relevant to cost:

Usage: The amount of quantum time used by this job. Quantum time is the duration a QPU is committed to fulfilling a user request.
Cost: The total cost of running this job.

Set up spending notifications

You can set up spending notifications to get notified when your account or a particular service reaches a specific spending threshold that you set. For information, see the IBM Cloud Account types page. IBM Cloud spending notifications must be used with other methods of cost management for several reasons:

The notifications trigger only after cost surpasses the specified limit.
Cost is submitted to the billing system hourly. Therefore, a long delay might occur between the job submission and the spending notification being sent.
The billing system can take multiple days to get information to the invoicing system, which might cause further delay in notifications. For more information about how the IBM Cloud billing system works, see Setting spending notifications.

Next steps

Recommendations

Review the plans available to IBM Quantum users.
Review suggestions to minimize job quantum time.
Learn how to set a maximum execution time on jobs.