Do I Register as Self Employed or just complete a Tax Return?
If you have just been employed, it is not likely you have been issued with a UK Tax Return. There are set criteria, so yes, I think you will have to register as self-employed, but it depends on your employment conditions at current job after changes. You or employer can’t decide you will be self-employed, even if you issue invoices. When you submit Tax Return, if it is decided you are employed, employer could face heavy financial penalties. Look at http://www.hmrc.gov.uk , then into employers’ section. There is a section on deciding status of potential employees. If you need further help, ask to see Status Inspector via local tax office for a ruling. If you are self-employed, you will need to do an annual Tax Return with both employed and self-employed pages in addition to the basic Return.