IR35 or Self employed

I am due to retire soon and have been offered one off contract work as and when needed from my employer . I’m confused if this will be classed as IR 35 or self employed?

Hi Jimbo,
IR35 is also known as 'off payroll working', makes sure that a worker (sometimes known as a contractor) pays broadly the same Income Tax and National Insurance as an employee would.
The rules apply if the worker who provides services to a client through their own intermediary would have been an employee if they were providing their services directly to that client. c
Please  have a look at:
Understanding off-payroll working (IR35)
Thank you.