No. You don't need to use a solicitor or claims management company to pursue a motor finance complaint. You can contact your lender directly free of charge. Some people choose to have a solicitor manage the process on their behalf instead, but it isn't a requirement.
In more detail
What can I do myself, without paying anyone?
You can complain directly to your lender in writing, setting out why you believe your agreement was affected by a discretionary commission arrangement or other issue.
Why might someone choose to use a solicitor anyway?
Some people prefer having someone else manage the correspondence, chase responses, and keep track of deadlines, particularly given how many people are expected to be affected by the redress scheme and the volume of complaints lenders are handling. It comes down to personal preference rather than necessity.
Does using a solicitor cost more than doing it myself?
Doing it yourself costs nothing beyond your own time. If you instruct a solicitor on a no win, no fee basis there is no upfront cost, but a fee is deducted from your redress if the claim succeeds. The SRA caps that fee on a sliding scale by the size of the redress, from 30% plus VAT on the smallest awards down to 15% plus VAT above £50,000, with a cash cap on every band. The fee that applies to your claim is set out in writing before anything starts, and you have 14 days from signing to cancel without charge. Whether that trade-off makes sense depends on your own circumstances and how comfortable you are managing the process directly.
Can I start the process myself and bring in a solicitor later if needed?
Yes, this is possible, though it's usually simpler to decide your approach early rather than switching partway through a live complaint.