Accreditation is a status given by one entity to the product or service of another. It usually permits the other to use the branding of the one on their product, service or CV. There are many accredited courses and the value of the accreditation varies greatly. Accreditation is not overseen by any independent third party or government department. It’s value is largely subjective.
Qualifications are developed and issued by Awarding Organisations and, in the UK, these are listed on the Regulated Qualifications Framework (RQF), which is the national framework of UK qualifications. The awarding organisations are in themselves regulated and overseen by The Office of Qualifications and Examinations Regulation often know as ‘Ofqual’ or colloquially as ‘the watchdog’.
The assumption of Professional status and competence requires a combination of things including:
Accreditation is normally used to convey a perception of quality/reliability and therefore trust in the subject, be it a product, service or person. However professional status and competence for a person is better demonstrated via a qualification due to the independence and quasi-governmental oversight of Ofqual.