[BUG] In Claude web interface, Usage Credits are being consumed even though my plan usage is only 25%

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

I'm seeing what appears to be incorrect billing behavior.

According to the Usage page:

• Plan usage: 25% used
• Weekly plan limit has not been reached.
• However, Claude has already started consuming Usage Credits.

I expected Usage Credits to be used only after the plan limit is exhausted.

<img width="1356" height="912" alt="Image" src="https://github.com/user-attachments/assets/dc98ccd7-f3b5-4ec3-9632-d8ec6ba6998f" />

Even though the plan usage is only 25%, Usage Credits are already being charged.

Current values shown:

• Plan usage: 25%
• The current session was at 60%
• Usage credits spent: €2.06
• Monthly spend limit: €0.10

What Should Happen?

• Continue using my normal plan quota until it reaches 100%.
• Only then start consuming Usage Credits (if enabled).

Error Messages/Logs

Steps to Reproduce

1. Enable Usage Credits.

1. Start a Claude Code session using Opus 5 with Extended Thinking.

1. Use the session until approximately 60% of the plan/session limit is consumed.

1. Open a second Claude web tab using the same account and the same Opus 5 model for a different task.

1. Run a Deep Research request in the second tab.

1. Observe the Usage page.

1. Despite the plan/session not being exhausted (around 60%), Usage Credits begin being consumed instead of continuing to use the remaining plan quota.

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

5

Platform

Other

Operating System

Other

Terminal/Shell

Other

Additional Information

1. Is this expected behavior?
2. Are Usage Credits intended to be consumed before the weekly plan limit is reached?
3. If this is expected, could someone explain how the plan usage and Usage Credits interact?

If this is not expected, this may indicate a billing or usage accounting issue.