This depends on several factors, including how you were mis-sold, the scale of your financial losses, and whether the financial adviser or pension provider that mis-sold your product are still in business.
If your financial adviser is no longer trading, you could claim up to £85,000 via the FSCS.
If your financial adviser is still trading but disagrees that they mis-sold your pension product, your case will be progressed via the Financial Ombudsman Service (FOS). Depending on when the mis-selling took place, the FOS could award up to £350,000 for a mis-sold pension.