Is a Level 6 diploma equivalent to a degree?
The word 'equivalent' hides three different questions. Each is answered separately here, so that you can tell which answer applies to your situation before you enrol.
Ask whether a Level 6 diploma is equivalent to a degree and you will get a confident yes from anyone selling one and a confident no from anyone with a degree. Both are answering a different question from the one you asked. There are at least three questions folded into the word equivalent, and they have three different answers.
Equivalent in level? Yes
The Regulated Qualifications Framework places every regulated qualification in England on a scale from Entry Level to Level 8. The placement describes the intellectual demand of the work: what the holder can be expected to analyse, evaluate, decide and defend. Level 6 is the band occupied by bachelor's degrees with honours. When an awarding body puts a diploma in that band and Ofqual accepts the placement, the judgement being made is that the diploma demands the same order of thinking.
This is not a marketing claim. It is what the number on the Ofqual register means. When a learner on one of these diplomas writes a five-thousand-word analysis of their organisation's financial decisions against the literature and is marked to Level 6 criteria, they are doing final-year work. In that sense, and only in that sense, the diploma is equivalent.
Equivalent in size? No
An honours degree in England is normally 360 credits: 120 at each of Levels 4, 5 and 6, earned over three years. A Level 6 diploma on this site is typically 120 credits, all of them at Level 6. Two of ours are smaller still, at 90 and 45.
So the diploma holder has done as much Level 6 work as a final-year undergraduate, and none of the Level 4 and 5 work that preceded it. That is a third of the credit. A university admitting to a top-up year is content with that arithmetic because the prior credit is exactly what a final year assumes; a recruiter comparing a candidate with a graduate is not obliged to be, and often is not.
Equivalent as an award? No, and it never will be
Degree is a protected word in the United Kingdom. Only institutions holding degree-awarding powers may put it on a certificate. OTHM and Qualifi are awarding organisations recognised by Ofqual; they are not universities and they hold no such powers. Their Level 6 awards are called diplomas because that is the honest name for them.
This is where the phrase degree-equivalent does its damage. It implies that a diploma may be presented where a degree is required, and that is simply not so. If a job description says degree, a visa route says bachelor's degree, or a professional body says honours degree, a Level 6 diploma does not satisfy the wording, and nobody should tell you it does.
So which question is yours?
Work out what you would use the qualification for, and then ask the right question of the right body.
If your aim is to enter the final year of a bachelor's degree, the question is one of level and subject match, and the answer comes from the university's admissions team. The diploma is designed for precisely this, and for the right degree it is a strong case.
If your aim is a job whose description says degree or equivalent experience, the question is whether a regulated Level 6 qualification plus your record will satisfy the recruiter. In our experience of the people we have advised it very often does, because the phrase itself invites judgement.
If your aim is anything that says degree without qualification, the question has already been answered, and the answer is no. Take the top-up first.
A note on how to describe it
Do not write "BA equivalent" on a CV. Write the award as the awarding body names it, with the level and the Ofqual number, and let the reader look it up. "OTHM Level 6 Diploma in Business Management (RQF Level 6, Ofqual 603/2179/9)" is accurate, verifiable and, to anyone who knows the framework, more impressive than a vague claim of equivalence would be.
If a form asks for your highest level of study, "Level 6" is true. If it asks for your highest qualification type, "diploma" is true. If it asks whether you hold a degree, the truthful answer is no, and the interesting conversation is about what you hold instead.
The honest summary
A Level 6 diploma is equivalent to a degree in the level of work it demands. It is not equivalent in size, and it is not the same kind of award. The first fact is what makes the top-up possible; the second and third are why the top-up exists. Anyone who tells you the diploma is a degree in all but name is either mistaken or selling something. Anyone who tells you it is worthless because it is not a degree has never sat a Level 6 assignment.