https://www.slab.org.uk/guidance/civil-legal-aid-how-we-calculate-income-and-whats-included/
Rule 1 of Schedule 2 to the regulations states that the person concerned income is taken to be the income they may reasonably expect to receive (in cash or in kind) during the period of computation.
The following notes give examples of the most common types of income and how we treat them.
The person concerned should supply
We will look at what they have earned since the start of the current tax year and use this information to calculate an average that we assume they will earn for the whole of computation period.
We can also take account of, for example, seasonal fluctuations, or periods when the person concerned is not paid, such as school holidays.
We take into account information contained in the latest set of accounts about the net profit your client has earned. We make certain adjustments to the net profit as follows:
If your client is newly self-employed and does not have a full year record, we can accept the figure the applicant says they draw each week or month from the business. We will ask for bank statements, to help determine these figures in the absence of accounts.
If your client does not have to have accounts made up, we will accept a copy of the information made available to HM Revenue & Customs and the tax assessment based on it.
We have a statutory requirement to disregard the state benefits and other government payments set out in Rules 5 and 7 of Schedule 2.
We use our discretion under Rule 16 of Schedule 2 to disregard other sources of income due to their nature.
You can view our published policy on discretionary disregard.