Guide · Spend
OpenAI vs Anthropic vs OpenRouter spend limits, compared
Three providers, three different places a spend cap can live. The table uses only what each provider's own docs say.
Checked November 2026. A cell says "not documented" when that provider's pages do not state it.
| Provider | Where the limit is set | Hard stop or alert only | Reset period | Per-key limit | Default on a new key | Docs |
|---|---|---|---|---|---|---|
| OpenAI | Organization limits, then Spend. Or Project settings, then Limits, then Spend. [1] | Both. A spend alert notifies you and traffic continues. A hard spend limit makes affected requests return 429. [1] | Monthly. A reached hard limit resets with the next monthly cycle unless you raise or remove it. [1] | No. The documented spend limit is the organization or one project. [1] | not documented | OpenAI, Spend limits |
| Anthropic | Billing page for the organization (platform.claude.com/settings/billing). A workspace can have its own spend limit. The default workspace cannot. [2] | Hard stop. The tier cap returns HTTP 429. A limit you set returns HTTP 400. This page does not document a spend alert that leaves traffic running. [2] | The tier cap pauses usage until 00:00 UTC on the first day of the next month. For a limit you set, the error states when access resumes. That clock is not documented here. [2] | No. [2] | not documented | Anthropic, Rate limits |
| OpenRouter | Security settings, Key safety, Set limit. A management key can also set limit and limit_reset on the key. [3] [4] | Hard stop. Requests with that key are rejected once it has used its credit limit. [5] | You choose daily, weekly, or monthly. Daily resets at midnight UTC. The clock for weekly and monthly is not documented. With no reset, the cap stays until you raise the limit. [4] [5] | Yes. The credit limit is on the key. [3] | not documented | OpenRouter, Security settings |
What none of them do
None of these pages documents a daily spend limit on one OpenAI key or one Anthropic key. OpenAI's limit is monthly and covers the organization or one project. [1] Anthropic's cap is monthly for the organization, or for a workspace other than the default workspace. [2] OpenRouter can cap one key, and that cap rejects the key's requests. It is not an email that leaves the request alone. [5]
Longer notes already on this site: the OpenAI hard spend limit, the Anthropic spend limit, OpenRouter spend alerts, and a daily budget per key.
Setup
OpenAI
For the organization, open Organization limits, then Spend, Edit spend limit. Enter the monthly amount. Turn on Enforce a hard limit if requests should fail, then Save. For one project, open Project settings, Limits, then the same Spend steps. A spend alert is a separate control and does not stop traffic. [1]
Anthropic
Open the Billing page, platform.claude.com/settings/billing. In Spend limits, click Adjust limit, or Set limit if none is set. The value cannot exceed the tier cap. Start is $500, Build is $1,000, and Scale is $200,000. Custom has no monthly spend cap. Workspace spend limits are separate, and the default workspace cannot have one. [2]
OpenRouter
On Security settings, open Key safety. Keys with no spend limit offer Set limit. A management key can set limit and limit_reset on PATCH /api/v1/keys/{hash}. limit_reset can be daily, and the daily example resets at midnight UTC. Weekly and monthly are named on the same key. [3] [4] [5]
Where BillCurfew fits
BillCurfew watches OpenAI, Anthropic, and OpenRouter. Pricing says xAI, Google Gemini, and DeepSeek are not supported. The product connects only those three providers, so AWS Bedrock is not supported either. It is not a proxy. Prompts and completions never reach it. It polls usage about every five minutes and emails you when a daily cap or a spike trips. A manual kill works on every plan, including Free. OpenAI deletion is permanent. Anthropic and OpenRouter disables are reversible. Auto-kill is on paid plans only and stays off until you turn it on. Free is $0 for one provider and one watched key, with no card. Solo is $19/month, Team is $49/month, and Agency is $149/month, each with a 14-day trial. See pricing and security.
FAQ
Does an OpenAI spend alert stop API traffic?
No. OpenAI says a spend alert sends a notification and API traffic continues. A hard spend limit is separate. When tracked spend reaches it, affected requests return 429. Enforcement is not instantaneous, so recorded spend can slightly exceed the limit.
Can Anthropic set a spend limit on one API key?
No. Anthropic documents a monthly spend cap for the organization, and a spend limit for a workspace. You cannot set a spend limit on the default workspace. That page does not document a per-key spend limit.
What happens when an OpenRouter key hits its credit limit?
OpenRouter says requests with that key are rejected until you raise the limit, or, when the limit is daily, weekly, or monthly, until it resets.
Sources
- OpenAI, Spend limits. https://developers.openai.com/api/docs/guides/spend-limits
- Anthropic, Rate limits. https://platform.claude.com/docs/en/api/rate-limits
- OpenRouter, Security settings. https://openrouter.ai/docs/guides/overview/auth/security-settings
- OpenRouter, Management API keys. https://openrouter.ai/docs/guides/overview/auth/management-api-keys
- OpenRouter, API Authentication. https://openrouter.ai/docs/api_reference/authentication