HTTP 100 Continue vs 402 Payment Required
HTTP 100 (Continue) is a 1xx Informational response, while 402 (Payment Required) is a 4xx Client Error response. 100 indicates that the server has received the request headers and the client should proceed to send the request body. This lets the client know it can continue with the request or abort if the headers were rejected. In contrast, 402 means that reserved for future use. Originally intended for digital payment systems, some APIs use it to indicate a billing or subscription issue.
Description
The server has received the request headers and the client should proceed to send the request body. This lets the client know it can continue with the request or abort if the headers were rejected.
When You See It
When a client sends an Expect: 100-continue header, the server responds with 100 before the client sends the body.
How to Fix
This is an interim response — no fix needed. The client should continue sending the request body.
Description
Reserved for future use. Originally intended for digital payment systems, some APIs use it to indicate a billing or subscription issue.
When You See It
On some APIs when a subscription has expired or payment is needed.
How to Fix
Check your billing status, update payment method, or upgrade your subscription.
Key Differences
100 is a 1xx Informational response, while 402 is a 4xx Client Error response.
HTTP 100: The server has received the request headers and the client should proceed to send the request body. This lets the client know it can continue with the request or abort if the headers were rejected.
HTTP 402: Reserved for future use. Originally intended for digital payment systems, some APIs use it to indicate a billing or subscription issue.
You encounter 100 when when a client sends an Expect: 100-continue header, the server responds with 100 before the client sends the body.
You encounter 402 when on some APIs when a subscription has expired or payment is needed.
When to Use Which
For 100 (Continue): This is an interim response — no fix needed. The client should continue sending the request body. For 402 (Payment Required): Check your billing status, update payment method, or upgrade your subscription.