Inside IR35
If someone's role is classed as full-time employment for an end client, HMRC will refer to this individual as being 'inside IR35'.
This ultimately means you must stick to the same government guidelines that any normal employee would. A person must ensure they pay the appropriate taxes for standard Income Tax and National Insurance on all earnings through what is classed as a 'deemed payment' at the end of the tax year.
Working out your deemed payment can be complicated, so it's best to speak to your accountant to make sure you get it right. Otherwise, you could face heavy investigation from HMRC.
Should an individual be found to be 'inside IR35' following the investigation, HMRC will order them to all Income Tax, NICs and interest they may have accrued, as well potentially a penalty which should have been paid during the accounting period in question.
Given HMRC can investigate as far back as six years, being found non-compliant can have huge financial consequences so diligence is highly recommended in this situation.
Outside IR35
When a person is outside IR35, HMRC will deem you as a genuine business. This will mean you will be working outside of IR35 rules.
In this situation, you will be able to pay yourself a salary, draw the remainder of income as dividends, and remain responsible for your taxes as usual.
Determining your position
There are key differences in a person's daily working routine that will clearly outline why they are working inside or outside IR35.
For example, if a person is working outside of the legislation, they would be the one to decide when and where they work rather than the client. This is not something you would often see in full time employment.
Additional points include having no obligation for ongoing work, how the worker is paid and whether they have access to corporate benefits.
If you are still unsure where you sit, there are tests you can take online which will assess your current work practices and let you know if you are 'inside' or 'outside' IR35.
HMRC recommends using their CEST tool which will take you through different requirements. In the past, HMRC has said that it will stand by the results of CEST, however, it's still worth being wary as they can still open up an investigation.