Each transaction that fails in PaymentsOS due to a provider decline will create a resource, except for transactions that fail with error codes between 400 - 500, such as a gateway timeout error.
In any other case, in the dashboard, you can extend the declined transaction section and see the error that caused the decline. There you will find the error category, and optionally, sub-category, provider response code, and the provider response description.
PayU's PaymentsOS category and subcategory are descriptive strings that should be used mainly for aggregating the responses, analytics, and instant retry purposes. PayU's PaymentsOS sub-category is used in some cases to provide extra details that are not contained in the main error category.
Depending on the provider response, you might receive the provider response code and the provider response description. These sections might contain the provider code and raw description.
Here you can find a list of PayU's PaymentsOS error categories and sub-categories and their full description (click on the link and scroll down until you see the headline "Response Categories").
Example of a declined charge in the Control Center.