HMRC have updated their information for the Self-employment Income Support Scheme.
The latest information can be found at: https://www.gov.uk/guidance/claim-a-grant-through-the-coronavirus-covid-19-self-employment-income-support-scheme?fbclid=IwAR2MZrkiYB4chU7oIs8DSzUaPYIpXasaDlwHid9oD66Qnmbzzr9Z8m4UebY
You can find further information about how HMRC calculates total income and trading profits for the scheme here: https://www.gov.uk/guidance/how-hmrc-works-out-total-income-and-trading-profits-for-the-self-employment-income-support-scheme?fbclid=IwAR2fxZ_ssrPNS9TjdHYTsnUeceeMPtFLmzeatt7XH-Bgv34TI0Qm1P39I88
I would like to add that people who have not submitted their Self Assessment tax return for the tax year 2018/19 must do this by 23 April 2020 or they will not be able to claim.
HMRC will aim to contact people by mid-May if they are eligible for the scheme and will invite them to claim using the GOV.UK online service. Alternative methods to claim for those who are not online will also be available.