# Errors

Common HTTP error codes returned by the Checkout APIs and their meaning.

Error responses have the same overall structure across Checkout APIs. General errors, such as `ResourceNotFound` are returned for all APIs. API-specific errors, are only returned for specific endpoints.

## General errors

#### 400 Bad Request

The following error codes can appear in responses with the HTTP status code `400`:

##### RequiredField

[type definition](/search.md?urn=ctp:checkout:type:RequiredFieldError).

##### DuplicateFieldWithConflictingResource

[type definition](/search.md?urn=ctp:checkout:type:DuplicateFieldWithConflictingResourceError).

##### InvalidInput

[type definition](/search.md?urn=ctp:checkout:type:InvalidInputError).

##### InvalidJsonInput

[type definition](/search.md?urn=ctp:checkout:type:InvalidJsonInputError).

##### InvalidOperation

[type definition](/search.md?urn=ctp:checkout:type:InvalidOperationError).

##### InvalidField

[type definition](/search.md?urn=ctp:checkout:type:InvalidFieldError).

##### MaxResourceLimitExceeded

[type definition](/search.md?urn=ctp:checkout:type:MaxResourceLimitExceededError).

##### ReferencedResourceNotFound

[type definition](/search.md?urn=ctp:checkout:type:ReferencedResourceNotFoundError).

##### SyntaxError

[type definition](/search.md?urn=ctp:checkout:type:SyntaxErrorError).

##### MissingProjectKey

[type definition](/search.md?urn=ctp:checkout:type:MissingProjectKeyError).

#### 404 Not Found

The following error code can appear in responses with the HTTP status code `404`:

##### ResourceNotFound

[type definition](/search.md?urn=ctp:checkout:type:ResourceNotFoundError).

#### 409 Conflict

The following general error codes can appear in responses with the HTTP status code `409`:

#### ConcurrentModification

[type definition](/search.md?urn=ctp:checkout:type:ConcurrentModificationError).

#### 503 Service Unavailable

The following general error codes can appear in responses with the HTTP status code `503`:

##### ServiceUnavailableError

[type definition](/search.md?urn=ctp:checkout:type:ServiceUnavailableError).

#### 500 Internal Server Error

The following general error code can appear in responses with the HTTP status code `500`:

##### GeneralError

[type definition](/search.md?urn=ctp:checkout:type:GeneralError).

## API-specific errors

The following errors are specific to certain API endpoints or operations.

### Payment Intents

#### 400 Bad Request

The following error codes can appear in responses with the HTTP status code `400`:

##### MultipleActionsNotAllowed

[type definition](/search.md?urn=ctp:checkout:type:MultipleActionsNotAllowedError).

### Transactions

#### 502 Bad Gateway

The following error codes can appear in responses with the HTTP status code `502`:

##### ConnectorFailed

[type definition](/search.md?urn=ctp:checkout:type:ConnectorFailedError).

##### PaymentFailure

[type definition](/search.md?urn=ctp:checkout:type:PaymentFailureError).

## Related pages

- [Area overview page with navigation](/checkout.md)
- [Previous page: Common types](/checkout/common-types.md)
- [Next page: Limits](/checkout/limits.md)
- [Search documentation and API specs](/search.md)