I live in the UK and I'm thinking of starting a business whilst in full time employment.

I've looked up the tax rules but I'm still quite unsure on everything. I was hoping someone could just clear up any misunderstandings I have.

I have two main questions:

1. If I start a business and I pay myself a salary from that business, does the tax amount get calculated based on my current salary as well? So if I currently get taxed 40% will everything I earn from the new business immediatly get taxed at 40% because of my current job?

2. If instead of paying myself a salary I pay myself in dividends, how much would that be taxed and will it be affected by my current jobs tax?

Regards,

I live in the UK and I'm thinking of starting a business whilst in full time employment.

I've looked up the tax rules but I'm still quite unsure on everything. I was hoping someone could just clear up any misunderstandings I have.

I have two main questions:

1. If I start a business and I pay myself a salary from that business, does the tax amount get calculated based on my current salary as well? So if I currently get taxed 40% will everything I earn from the new business immediatly get taxed at 40% because of my current job?

2. If instead of paying myself a salary I pay myself in dividends, how much would that be taxed and will it be affected by my current jobs tax?

3. If the source of my income is from building my own software (not selling it, using it to generate ad revenue or paid services to users) would IR35 ever come into play?

Regards,