Every word they use, in words you use.

One case brought on behalf of lots of people who were harmed the same way by the same company.

Why it matters: Alone, your £200 is not worth suing over. Together, thousands of people’s £200 is a case a company has to answer.

You are only part of the claim if you actively sign up.

Why it matters: Most UK group claims work this way. If you do nothing, you get nothing — which is why registering matters.

You are already in the class, and you have a window to remove yourself if you would rather not be.

Why it matters: The opposite of the above, and it catches people out. Doing nothing keeps you in.

One person or organisation who formally brings the claim for everybody in the group.

Why it matters: You are not on the hook for running the case. They are, and their lawyers do the work.

Whether the specific facts of your situation put you inside the group the claim covers.

Why it matters: It is usually about dates, products and whether you were a customer — not about how much you lost.

Many individual claims about the same wrongdoing, run together but assessed one by one.

Why it matters: Unlike a group claim, your payout depends on your own circumstances, so it takes longer.

The specialist UK tribunal that hears competition claims, including most large consumer group claims.

Why it matters: If your claim is in the CAT it is a real, formal case with a judge — not a marketing exercise.

The stage where a judge decides the claim is fit to run as a group.

Why it matters: Until a claim is certified it might never proceed at all. Any promise of money before this point is empty.

The process where each side has to hand over its documents, including the unhelpful ones.

Why it matters: This is where the evidence a company would rather bury tends to surface. It is also slow.

The legal time limit for bringing a claim — often six years, sometimes from when you could reasonably have discovered the problem.

Why it matters: Once it expires the claim dies regardless of merit. It is the single best reason not to wait.

A formal letter setting out the claim and giving the other side a chance to respond before proceedings start.

Why it matters: A sign a claim is progressing properly rather than sitting in someone’s inbox.

An agreement where the lawyers are only paid if the case succeeds.

Why it matters: You pay nothing up front and nothing if it loses. It is why joining costs you nothing.

An investor who pays the legal costs of running the claim in exchange for a share of any winnings.

Why it matters: It is why huge claims can be brought without claimants paying. Their cut comes out of the settlement.

Insurance that covers the other side’s legal costs if the claim loses.

Why it matters: It is the thing that means a lost case does not land you with a bill.

An agreement to pay a sum and end the case, without a judge ruling who was right.

Why it matters: Most claims end here. It is normally faster and more certain than fighting to judgment.

The amount of money — as opposed to whether the company is liable at all.

Why it matters: Liability and quantum are argued separately, which is why “we won” and “here is your money” can be a year apart.

The process of getting money from a settlement pot into individual people’s bank accounts.

Why it matters: The only point at which anyone should ever ask you for bank details — and it comes after a court has approved it.

A free request forcing an organisation to give you the personal data it holds on you.

Why it matters: Genuinely useful. It is how you get your old finance agreement or contract when you have lost the paperwork.

A programme a regulator forces a company to run, paying money back to customers directly.

Why it matters: No lawyers needed and no fee taken — but the window to claim is usually short.