When processing a personal injury claim, a salaried person can easily get a letter from the employer and pay stubs to prove lost income. It won't be that easy for you, however, if you are a self-employed person, and you will have to be creative with your evidence. Here are some forms of lost income evidence you can use if you are self-employed:
You can use evidence of canceled appointments, meetings or conferences where you might have earned some money. The evidence may come in the form of cancellation letters or emails explaining your absence or queries from your business partners or clients. For example, if you are an energy consultant who missed an appointment with a local business due to an accident, you can use evidence of the value of the consultation for your lost income claim.
Drop In Invoices
If you have records of your invoices over the past year or months, you can use them as evidence of what you might have earned had you not been injured. For example, if you are a freelance writer who kept up-to-date invoices before their injury, and you haven't sent any invoice over the last couple of months or so, you can use this as evidence of lost income.
Previous Tax Returns
You shouldn't worry about evidence of lost income if you have been paying your taxes faithfully. Just get the most recent personal income tax returns (one or two years will do), specifically the section dealing with gross income, and you are good to go. You can then calculate your monthly or weekly average (based on the tax returns) to show the court how much you lost due to your injury.
You deserve to be compensated not only for the actual work/income you lost due to your injury but also for the opportunities you lost. For example, a job interview is an opportunity; it isn't actual work, but you should still be compensated for it. The difficulty with job opportunities is that they are difficult to quantify because you can't calculate the probability that you would have got the job. At the same time, the defendant can't say with certainty that you would not have got the job. Therefore, you might not get exactly what you would have been paid for the job, but you will definitely get some sort of compensation for it.
Note that you have to prove every claim you make if you are to be compensated for it. Your personal injury lawyer can help you gather the evidence you need and prove your case.