https://www.slab.org.uk/faqs/1-your-first-appointment-with-a-solicitor/
Check with the solicitor before your appointment so you know exactly what to take with you.
In your application for legal aid, we need to see evidence of your income and capital.
We also need to see information about your main outgoings, such as payment towards loans or payments for childcare.
You may need to take along information about the following for both yourself and your partner (unless you're separated or they are the person you have a legal problem with):
If you’ve been charged by the police you should also take any paperwork that the police, courts or procurator fiscal have given to you.
If you are in custody your legal aid solicitor will tell you what you need to do to show what your financial situation is.