The First-tier Tribunal (Social Entitlement Chamber) is completely independent of the DWP. A judicial panel consisting of a Judge, a Doctor, and a Disability Specialist examines your case afresh. Ministry of Justice statistics show that over 70% of PIP hearings succeed in overturning DWP decisions.
You must lodge your appeal within one calendar month of the date on your Mandatory Reconsideration Notice. You can submit your appeal online via GOV.UK or by posting Form SSCS1 to HMCTS.
Form SSCS1 asks whether you want a decision "on the papers" or an "oral hearing" (in person or via video link). Never choose a paper hearing: the success rate for paper hearings is only ~35%, compared to over 70% for oral hearings where the panel can speak with you directly.
When the Tribunal overturns the DWP decision, the award is backdated to the date of your original claim. Backdated sums frequently exceed £3,000 to £8,000. By handling the appeal yourself or using fixed-fee self-representation software like Casewright (£49 flat), you retain every single penny of your backpay rather than handing 25-40% to commercial claims brokers.