It is a legal requirement is to provide the tenant with the How to Rent guide in hard copy or by email before the tenancy start or after the viewing immediately. However, only where the tenant has notified the landlord or agent of an email address where they are content to accept service of notices or documents under the tenancy. It also gives landlords and tenants a summary of their rights and responsibilities. As a landlord / managing agent, you'll need to give tenants a copy of this guide at the start of a new tenancy alongside the 'prescribed information', which confirms the key details of the deposit.
What other documents do I need?
Can I serve a how do you Rent Guide late?
If a landlord or their agent fails to serve the guide as detailed above no valid s. 21 notice can be served. However, there does not appear to be a time limit on serving the guide and so it may be possible to serve the guide late and immediately follow it with a section. 21 notice.
Link to download lates How to Rent Guide, which is changed since Covid-19 : https://www.gov.uk/government/publications/how-to-rent