Multiple sources of income

I am a co-owner of a company which I work for and currently work part time for a University. Last year I worked part time for a corporate company and thus I have multiple sources of income. I find it extremely difficult to understand where each of these earnings should go etc.

Do you receive IRP5's for all the income?

Unfortunately I dont.

If you invoice and have records of the income earned then you would make use of the Business Income section of the tax return where you would include the incomes earned and then all the related business expenses.