You were named as the other party on a record of one specific piece of work, and you are being asked one question: did it happen.
Answering takes about thirty seconds. You do not need an account, there is nothing to install, and there is nothing to pay.
What Credda is
Credda is a record of work people said they would do and whether they did it. A locum hygienist, a shopfitter, a care worker, a self-employed electrician: anyone whose living depends on being reliable can keep a record of it and show it to the next person deciding whether to trust them.
That record is only worth anything because the people on the other side of the work confirm it. Which is why an email landed in your inbox.
Why you
Credda does not let anyone confirm their own work. It is blocked outright, not quietly discounted. So when an electrician says she rewired your shop and finished on the Friday she promised, the only way that becomes anything more than her own word is if you say so.
The person who asked you entered your email address themselves, because they named you as the person who was there.
What you are being asked
The email says which of these it is.
Did this get delivered. Someone marked a job as done and named you as the client or the other party.
Was this invoice settled. The same idea, about money rather than work.
Is this part of their history true. Someone listed a job, a qualification, a project or an award and named you as the person who would know. For a job that is usually a former manager, client or colleague. For a certificate it is the body that issued it.
Do you agree these are the terms. Sometimes the ask comes before the work, not after, and you are being asked to confirm the written terms match what you agreed.
If the same person named you on several records, you get one email listing them all, with a separate yes and no for each. You can answer some and leave the rest.
What you are not being asked
This is the part most people assume wrongly.
There is no rating. No stars, no marks out of ten, no box asking what you thought of them.
You are not being asked for an opinion about the person. You are being asked whether one specific thing happened.
You are not becoming a reference for their future work. Confirming does not mean you would use them again, and you are never asked that.
The rule inside the product is that a witness confirms a fact, never a verdict. Nothing on the page asks you what should be done about anyone.
Do I need an account
No. Reading the request, confirming it, correcting a detail on it and declining it all work from the link in the email with no sign-up.
That is deliberate. Making a stranger register in order to answer a question about somebody else would turn the question into a way of collecting people.
After you answer you are offered a record of your own, free, and you can ignore that. Credda will not offer to look anyone else up. There is no search box for people, and no list of bad customers or unreliable workers anywhere in the product.
What happens after you answer
Your answer is recorded against that one record.
Whether it also counts as independent evidence is decided by automatic checks on Credda's side, not by you and not by the person who asked. A confirmation can be recorded and still not count. Neither of you is told which check applied, on purpose: publishing the rules would be a set of instructions for getting round them.
So the honest sentence is that confirming records what you said. It does not hand anybody a guaranteed pass.
Confirm, decline, correct or ignore sets out exactly what each of your four answers puts on their record.
If you would rather not
Declining is a complete answer and needs no explanation. It is not a complaint and nothing is recorded against the person for it. Ignoring the email is also allowed, and silence is never turned into a yes.
One thing Credda is not
It is not a background check and not a credit reference. Nothing on a Credda record is checked against criminal, credit, identity or public records, and no such check has been done. It is a record of outcomes that the person themselves chooses to show, and they can withdraw it at any time.