The short answer
A sales pack is information a seller will have to provide before listing: property searches, a condition report, digital logbook information, and leasehold or freehold details. There is no start date. The government's roadmap of 19 June 2026 places it in the phase running to the end of this Parliament, subject to legislation.
Through 2026 the work is voluntary rather than statutory: non-statutory guidance on listing quality, an agreed list of what sellers can provide upfront, and a non-statutory Code of Practice for agents. Binding conditional contracts are intended to follow, but only once packs have been tested and embedded.
Why this matters for your purchase
This is the kind of thing a PropM8 Property Intelligence Report is built to surface early, before solicitors, surveyors or lenders are involved, while it still costs nothing to walk away.