The question tends to arrive in one of two situations. Either you are considering sitting the test early — a cycle or more before the intake you actually want — and wondering whether the certificate will still count by the time you use it. Or you already hold a result from an earlier cycle and are about to attach it to a new application, assuming it travels. Both plans are sensible. Both rest on something that is easy to take for granted and cheap to confirm: how long the result in your hands is actually accepted, and by whom.
There are two clocks, not one
The first clock belongs to the certificate. The dMAT's official information and terms are where any stated validity period lives, and if one is published, that is the authoritative figure for the document itself. Check it there rather than inferring it from what a test in another country does, because nothing about another admissions exam's shelf life is evidence about this one.
The second clock belongs to whoever is receiving your file. A university, a department, a scholarship body or a verification procedure can apply its own rule about how recent a result must be, and that rule is allowed to be stricter than the certificate's own. This is the part that catches people. A document can be perfectly valid in the issuer's terms and still be declined by a programme that only accepts results from within a shorter window.
Which means the number that governs your plan is not the longer of the two. It is the shorter one, applied per recipient. There is no single page that states it for your particular case, and that is not an oversight — it is two independent bodies setting their own conditions, which is normal for admissions paperwork and simply has to be read twice.
Check it before you build a plan on it
Start with the official dMAT pages and the terms and conditions, and note what they say about the certificate's validity in the words they use. Then go to the receiving side: the APS procedure if it applies to you, and each programme's admissions requirements separately. "Each" is doing real work in that sentence — departments within one university often differ, and two programmes you consider interchangeable may not treat an older result the same way.
Write down what you find rather than trusting your memory of it. The date you sat, the release date of the certificate, any stated validity, and then one line per programme: what it requires, the URL you read it on, and the date you read it. That record takes ten minutes and settles arguments with yourself later.
If the sources appear to contradict each other, resist the urge to pick the convenient one. The approach in when sources disagree about dMAT eligibility applies directly here: prefer the official and the specific over the general and the second-hand, and get the binding answer in writing from the body that will actually decide. It is also worth confirming which admissions round your reading applies to, since requirements attach to an intake rather than to the exam in general — which intake does the dMAT requirement cover sets out why that distinction matters more than it looks.
When the result will not cover the intake you want
Suppose you check and the answer is unwelcome: the certificate you hold, or would hold, falls outside what your target programme accepts. You have two honest options and one bad habit to avoid.
The first option is to sit the test in a later cycle so the result lands comfortably inside the window. This costs a fee and a preparation period, and it is the clean answer when the gap is large. If a retake is on the table for any reason, how to decide whether to retake the dMAT is the more careful way to think it through than deciding on a bad afternoon.
The second is to ask. Write to the admissions office, state the date you sat and the date on the certificate, and ask directly whether that result is accepted for the intake you are applying to. A clear question with dates in it usually gets a clear answer, and a written confirmation is worth considerably more than a plausible inference from a webpage.
The habit to avoid is assuming the older result will be waved through because it technically exists. That assumption is only discovered to be wrong at the point where it is too late to do anything about it — which is the same failure mode as a result that arrives after a deadline, reached from the opposite direction.
If you are deliberately sitting early
Sitting early to get the exam out of the way can be a good strategy, but only if two things hold: the result will still be valid when you need it, and the result is one you would be happy to be stuck with. A certificate does not improve while it waits. Sitting a cycle early while underprepared can leave you holding a weak score that is valid for exactly the application you cared about, which is a worse position than not having sat at all.
So check the validity question first, and check your readiness honestly second. A free practice mock gives you a baseline before you commit a fee to a real sitting, and what the dMAT score, percentile rank and certificate actually report is worth reading before you decide what an acceptable outcome looks like.
The honest summary is that "how long is it valid" is not one number you can look up once and reuse. It is the issuer's rule and your recipient's rule, checked against the intake you are actually applying for, and confirmed in writing where anything rides on it. That is a slightly tedious half hour, and it is far less tedious than discovering the answer from a rejection.
