31% said the biggest obstacle to better support was staff lacking awareness, and 22% said manager confidence.
Nick Henderson-Mayo, head of compliance at VinciWorks, said: “There is a pattern here that should concern HR and compliance leaders.
“Organisations who say they are neurodiversity-friendly should have the evidence to back this up.
“With the Employment Rights Act putting more power in the hands of workers, firms should be prepared to show a tribunal how supporting neurodiversity in principle aligns with practice.”
Only 39% of organisations had delivered any neurodiversity training.
Of these, just 21% included it in ongoing programmes.
38% said they wanted to provide training but had not done so, and 14% had no plans to train.
Henderson-Mayo added: “A single standalone session is unlikely to change how a manager behaves when a neurodivergent employee comes to them with a problem.
“What changes behaviour is repeated exposure, practice and the confidence that comes from knowing what effective support for neurodivergent staff looks like.
“Effective training covers how to open the conversation, how to approach a needs assessment, and how to review adjustments over time. That is how employers can evidence support.”
Barriers to improving support included lack of awareness (31%), manager confidence (22%), time and budget constraints (16%), unsupportive culture (14%) and unclear policies (11%).
Only 6.5% said their organisation had no major barriers.
Henderson-Mayo said: “Like any workplace issue, a policy is useless on its own.
“It has to be backed up by strong and regular communication, training for managers and employees alike, and effective routes for accessing support.
“This is what an employment tribunal will look for, and we can expect to see a lot more neurodiversity at work issues being adjudicated in the future.”
Henderson-Mayo added: “The Employment Rights Act increases the likelihood that an employment dispute, from performance to pay, will reach a tribunal.
“Where neurodiversity forms part of the claim, employers will be expected to evidence that support worked in practice, not just on paper.”