Once you have decided to pay for a private assessment rather than continue waiting, the question is no longer whether to go private, but which provider deserves your trust. Choosing well means looking past the marketing and asking a handful of practical questions, from who is actually assessing what you can expect once the report lands in your inbox.
We work with children, young people, and adults every week at Spectrum Assessments, and this guide sets out exactly what we tell families to check before they commit to any provider.
If you would like a clearer picture of what our autism assessment process involves before working through the checklist, that is a good place to start. Otherwise, the criteria below will help you compare providers with confidence.
What a Credible Private Autism Assessment Involves
A credible private autism assessment is a multi-stage clinical process, not a single appointment or an online questionnaire. Autism, also written as autism spectrum disorder or ASD, is diagnosed according to the DSM-5 diagnostic criteria by clinicians drawing on information from several sources, not a single conversation or checklist.
A sound pathway has five stages: an initial screening or free telephone consultation to establish suitability; a structured developmental history interview; direct observation or a structured clinical interview with the person being assessed; a multidisciplinary team review of the evidence; and a full written diagnostic report. Appointments usually span two or three sessions, with the report following afterwards. Any provider who offers a diagnosis after a single 60-minute conversation is not following a NICE-aligned pathway.
The Provider Checklist to Work Through before You Book
Every point below is something you can ask a provider directly, by phone or email, before you part with a deposit.
- Is the assessment reviewed by a multidisciplinary team, or signed off by one clinician working alone?
- Which professional register are your clinicians on, and what is their registration number?
- Does your pathway follow NICE CG142 for children and young people, or NICE NG87 for adults?
- Which standardised instruments do you use, and who administers them?
- Is a full written diagnostic report included in the fee, and when will I receive it?
- Is the quote a single all-in fee, and which items are billed separately?
- What post-diagnostic support, feedback, or signposting is included?
- Can you assess co-occurring conditions such as ADHD in the same pathway?
Ask for the answers in writing. A provider confident in its pathway will send a written summary without hesitation, and that document becomes your comparison sheet.
| Quick tip: Ask for each clinician’s HCPC public register number and check it yourself; it takes under a minute and shows any restrictions on practice. In England, you can also look up a clinic in the Care Quality Commission (CQC) directory, which lists the registered service rather than individual clinicians. |
Multidisciplinary Team Review versus a Single Assessor
This is the biggest difference in quality between providers. NICE guidance on autism diagnostic assessment, set out in CG128 for children and young people and CG142 for adults, describes this as the work of a team with a range of professional skills and experience, rather than a single clinician forming a view in isolation. A multidisciplinary team typically brings together input from clinical psychology, speech and language therapy, paediatrics or psychiatry, and occupational therapy, where sensory needs are prominent.
The team review matters most in the cases that are hardest to call: a child who presents differently at home and at school, or an adult who has masked for decades. A second clinical opinion on the same evidence reduces the risk of both a missed and an over-called diagnosis. Our clinicians have more than ten years of NHS and private experience, are registered with the HCPC, and hold membership of bodies including the Royal College of Speech and Language Therapists. Every case, including each child’s autism assessment, goes to team review before a report is written.
Recognised Diagnostic Instruments and NICE-Aligned Pathways
Two instruments are widely regarded as the gold standard in autism diagnosis, and you should expect to hear both named. The Autism Diagnostic Interview Revised (ADI-R) is a structured developmental history taken from a parent or long-standing informant, covering early communication, social development, and repetitive behaviours. The Autism Diagnostic Observation Schedule, Second Edition (ADOS-2) is a structured, scored observation carried out directly with the person being assessed.
The two do different jobs, which is why the combination is stronger than either alone. Questionnaire-only or single-interview assessments rely on self-report or a single informant’s recall, providing thinner evidence than a GP, school, or local authority will expect to see. For adults, where a childhood informant may be unavailable, a sound pathway substitutes a detailed retrospective history, collateral information where possible, and the clinician’s experience of masked and late-recognised presentations. That is how we structure an adult autism assessment, in line with NICE CG142.
What the Written Diagnostic Report Should Contain
The report is the deliverable you are paying for, so ask to see an anonymised sample. A sound report states the instruments used, names the clinicians involved and their professional registrations, sets out the DSM-5 criteria considered, and shows the clinical reasoning behind the conclusion rather than simply asserting it.
It should also carry a recommendations section written for practical use: reasonable adjustments for school or the workplace, communication and sensory strategies, and any onward referrals worth pursuing. Confirm the report is included in the quoted fee, how long it takes to arrive, and whether the provider will write to your GP on request. NHS services, schools, and local authorities consider private reports on their clinical merit, and decisions about onward care, such as medication or shared-care agreements, are made locally.
Pricing Transparency and the Extras to Ask About
Compare total cost, not headline cost. Items commonly billed separately include report writing, the feedback appointment, a GP letter, a school or nursery observation, follow-up reviews, and late cancellation fees. A single figure that covers all of these is not always the cheapest on paper, but it is the only one you can reliably compare.
| Ask three questions: Is this an all-in fee or staged payments, which extras sit outside it, and what happens to the fee if the assessment concludes without a diagnosis? On that last point, a report should still be produced, still explain the evidence, and still discuss alternative explanations for the difficulties raised. |
Green Flags and Warning Signs in Provider Comparison
Use this as a scoring sheet across your shortlist, treating the right-hand column as questions to raise rather than accusations.
| Criterion | What a credible provider looks like | Warning sign |
| Assessor make-up | Multidisciplinary team review of every case | One clinician assesses, decides, and reports alone |
| Instruments | ADI-R and ADOS-2, or a clearly justified adult equivalent | Online questionnaires only, or instruments not named |
| Pricing | Written all-in fee with extras listed | Quote given verbally, extras revealed after booking |
| Report | Full written report included, sample available | Report charged separately or a summary letter only |
| Registration | Registration numbers shared on request | Vague references to “our specialists” |
| Post-diagnostic support | Feedback session and signposting included | Report emailed with no follow-up contact |
| Outcome claims | No prediction before assessment | Implied or promised diagnosis |
If a provider scores well on 6 of the 7 rows and can explain the exception, you are in safe territory.
Post-Diagnostic Support and What Happens after the Report
Ask what exists after the report, because this is the stage most comparison exercises skip. At minimum, expect a feedback session where the findings are explained in plain language, written signposting to relevant services, and a window in which you can come back with questions.
For adults, next steps often involve workplace adjustments, an Access to Work application, and the post-diagnosis guidance published by the National Autistic Society. For children, the practical work is usually sharing the report with the school, feeding it into the SEN support process, and considering referrals for co-occurring difficulties such as sleep, anxiety, or sensory needs.
Self-Pay Private Assessment Compared with NHS Right to Choose
In some circumstances, you can access a private provider at no direct cost through NHS Right to Choose. This is an NHS-funded referral in England to an approved independent provider, and it requires your GP to make the referral; self-pay does not. Eligibility and availability vary by age and area; some services do not accept under-18s, and waiting times still apply, though they are often shorter than local NHS queues.
Self-pay gives you control over timing, choice of clinician, and the design of the pathway, including whether autism and ADHD are assessed together. Both routes should meet the same NICE standards, so the checklist above applies to whichever you use. If you are weighing a combined pathway, our ADHD assessment route is aligned to NICE NG87 and can run alongside an autism assessment rather than after it.
How Spectrum Assessments Meets Each Checklist Point
Taking the criteria in order: every case is reviewed by our multidisciplinary team; our clinicians are HCPC-registered and will share their registration numbers; and our pathway is built around NICE CG128 and CG142. We use the ADI-R and the ADOS-2, and a full written diagnostic report suitable for your GP, school, or local authority is included in the fee.
Appointments are available online or in person at our clinic, and we begin with a free telephone consultation to establish whether an assessment is appropriate before anyone commits. We assess children, young people, and adults aged 18 and over on a self-referral basis, with ADHD assessed alongside autism where this is requested. We make no claims about the outcome of any assessment before it is completed.
