I’ve had a go at updating the section 21 validity flow chart. It now incorporates the effect of the Tenant Fees Act 2019 (which turned out to be more complicated to do than I thought – I think it works, but constructive criticism welcome), and updates notes on EPCs and gas safety certificates.
It will need revising again for 1 June 2020, due to the transitional provisions of the Tenant Fees Act, alas.
The new flowchart is in word form (with working hyperlinks) or pdf form (with broken hyperlinks), and also available on the flowchart page.
[Edit – slight tweak to TFA page on 4 September 2019]