🐛 Bug: Claude Code charges users twice - API billing AND prepaid credits consumed simultaneously

[Kari-Basavaraj]

🐛 Bug Report: Double Billing on API-Based Login

Summary

Users on API-based billing (pay-per-usage) are being charged twice for every request — once via API billing (correct) and once via prepaid credits (incorrect).

---

🔗 Related Issues

This issue has been reported multiple times but remains unresolved:

Issue	Title	Relevance
#20976	"Max plan shows as API Usage Billing"	EXACT same issue
#7719	"API credits consumed despite Pro subscription"	Same dual-billing pattern
#5300	"PRO account shows Credit balance too low"	Credit depletion on paid plans

---

📊 Evidence: Billing Proof

Test Session 1 (15 minutes of usage):

Metric	Before	After	Change
Prepaid Credits	$1.53	$1.12	-$0.41 ❌
API Usage	$8.71	$9.12	+$0.41 ✅

Test Session 2 (with forceLoginMethod: "console"):

Metric	Before	After	Change
Login managed API key	$0.00	$0.26	+$0.26
Prepaid Credits	$4.84	$4.58	-$0.26 ❌

Result: Exact dual charge — same amount charged to both payment methods even with forceLoginMethod set.

---

🔄 Steps to Reproduce

1. Have API billing enabled ($100/month limit)
2. Log in to Claude Code using API-based billing (pay-per-usage)
3. Use Claude Code for 10-15 minutes
4. Check both:
   • API billing: https://console.anthropic.com/settings/plans
   • Prepaid credits: https://console.anthropic.com/settings/billing

Result: Both show charges for the same usage (approximately equal amounts)

---

✅ Expected Behavior

• ✅ Only API usage increases
• ✅ Prepaid credits remain unchanged
• ✅ Single billing method

❌ Actual Behavior

• ❌ Both prepaid AND API usage increase
• ❌ Same usage charged twice
• ❌ Prepaid balance can go negative

---

🔍 Root Cause Analysis (Suspected - Unconfirmed)

We suspect (but cannot confirm) this may be related to an authentication split:

Suspected Issue:

• Main Claude Code process: Uses API key → API Usage Billing ✅
• MCP OAuth servers: Use OAuth tokens from .credentials.json → Prepaid Credits ❌

---

❌ Failed Fix Attempts

Attempt	Action	Result
1	Delete ~/.claude/.credentials.json	OAuth tokens regenerated automatically ❌
2	Set "enableAllProjectMcpServers": false	OAuth tokens still regenerated ❌
3	Empty OAuth credentials manually	Full OAuth configs restored from plugin files ❌
4	Set "forceLoginMethod": "console" in settings.json	Dual billing still occurs ❌
5	Export ANTHROPIC_API_KEY in ~/.zshrc	Key shows "Never used" - Claude Code ignores it and uses login managed key ❌
6	Run /logout and restart	Still charges both API key AND prepaid credits ❌

Key Finding from Attempt 4-6:
Even with forceLoginMethod: "console" configured:

• Claude Code shows "API Usage Billing" in status bar ✅
• Login managed API key is charged ✅
• Prepaid credits STILL consumed ❌ (same amount deducted from both)
• Environment variable ANTHROPIC_API_KEY is completely ignored

Why Client-Side Fixes Don't Work:

• Official plugins are closed-source
• OAuth server URLs are hardcoded in plugin code
• No API key configuration option exists for plugins
• Plugins auto-load and override manual credential changes
• forceLoginMethod doesn't prevent OAuth-based charges

---

💥 Impact

Impact Area	Description
💰 Financial	Users charged 2x for requests
🔇 Silent Failure	No warning before credit depletion
⚠️ Negative Balance	Users hit -$0.21 without ever buying credits
🔒 Trust	Unexpected charges erode user confidence

---

🌍 Environment

• OS: macOS (likely affects all platforms)
• Claude Code Version: v2.1.31 (Feb 2026)
• Billing Type: API-based billing (pay-per-usage via console.anthropic.com)
• API Key: Configured in ~/.zshrc as ANTHROPIC_API_KEY
• Settings: forceLoginMethod: "console" in ~/.claude/settings.json
• Regression Started: ~February 2-3, 2026
• Frequency: 100% reproducible

---

🙏 Requested Fix

1. Immediate: Audit billing routing to identify why dual charges occur
2. Root Cause: Ensure API billing users are only charged via API billing
3. Refund: Consider refunding incorrectly charged prepaid credits for affected users

Potential Solutions (for Anthropic team to evaluate):

• Option 1: Make OAuth MCP servers use API billing when API key is present
• Option 2: Allow API key auth for official plugins instead of OAuth
• Option 3: Skip prepaid charges for OAuth requests when API billing is enabled

---

📎 Additional Notes

• This is a regression — worked correctly before Feb 2-3, 2026
• Possibly related to Jan 2026 platform changes that restricted OAuth tokens to Claude Code only
• The issue is server-side — no client-side workaround available
• Only working workaround: Uninstall OAuth-based plugins (but loses valuable integrations)

---

🔄 Additional Issue: Broken /login Flow

When running /login command and selecting "Anthropic Console account • API usage billing":

Expected: Should provide an API key token to copy for authorization
Actual: Redirects to "Buy credits to get started" page

This indicates the system is incorrectly routing API billing users through the credits purchase flow instead of the API key authorization flow.

[nCubed]

I’m on the Claude Pro plan with extra usage enabled, and I’m seeing related billing behavior that may stem from the same credit-prioritization issue.

What’s happening

• I hit my Pro session usage limit.
• I have a prepaid extra-usage balance already funded.
• When I continue the session, Claude charges me in real time instead of drawing from my prepaid balance.
• My prepaid balance does not decrease.

Expected behavior

Prepaid extra-usage credits should be consumed first before any real-time billing occurs.

Actual behavior

Real-time billing is applied immediately, and the prepaid balance remains unused.

This appears to be a failure in credit-priority logic rather than double billing, but may share the same underlying cause.

[Kari-Basavaraj]

Update: Bug reported via /bug command

Feedback ID: ba6dda42-1ef6-4628-a285-a8b343501ab9
Submitted: Feb 13, 2026 11:55 AM IST
Version: v2.1.41

This internal bug report links to this GitHub issue for engineering team visibility. @claude

[RalphMao]

I also encountered similar bug - it starts using API even though I am using Oauth to login

[romitsenmi]

Facing an exactly similar issue - kindly look into this. It uses API even though I have confirmed with /status that it is on Claude Pro subscription.