# Why Will Developers Encounter Error 429 When They Call a Subscribed API?
# Introduction
This guide introduces why developers will encounter Error 429 when they call a subscribed API and what could be done.
# Why Will Developers Encounter Error 429?
Error 429 is an HTTP response status indicating the user has sent too many requests. This happens when a developer has used up all the quota in the subscribed plan.
# What could be Done If Providers Would Like to Allow Developers to Continue Using the Same API?
When the quotas of the current plan for a subscriber is used up, and providers wish to provide the subscriber with a top-up API subscription plan for extra quotas, providers may follow the following steps:
- Assumption: Both current plan and the new top-up plan are free plans
- Create a new Unlisted Pricing Plan on the same API.
- Provide the Unlisted Plan URL to the developers.
- Developers could then subscribe to the new unlisted subscription plan that you created.
- Developers would have a new active plan with more quota so that they can continue using the same API.