But, according to an evaluation published this week, the service needs to create a higher profile, with some parents describing it as a "well-kept secret" from which many others could benefit.
Information about the support available should be offered to parents by local authorities and health agencies as soon as their child is identified as having difficulties, it was also suggested.
Two reports - one on the evaluation, the second into the future delivery of advice and information services for additional support needs in Scotland - advocate continued funding of Enquire by the Scottish Executive.
However, the evaluation suggests that some parents need more intense one-to-one support than Enquire currently offers and there is a need for services with an advocacy remit to complement its work.
Concerns were also expressed about Enquire's ability to provide an adequate service for parents with communication difficulties or in very disadvantaged circumstances. Overall, much greater cross-referral between agencies was seen as highly desirable.
Enquire, while recognised as being a national service, also needed to review whether it could provide more local information, it was suggested.
"Some local authority staff felt that enquiries about local matters should be referred back to them, since Enquire was a national service and was unlikely, therefore, to have enough insight into local authority policy and practice," the report stated.
Local education officials are not so well-informed either. "For example, a parent reported that a request for an individualised educational programme was turned down without a proper explanation, and another request for a personal learning plan was rejected out of hand."
Local authority staff feared that Enquire might encourage parents to adopt "an adversarial stance". In turn, the researchers found a continuing reluctance "in certain parts of the education system" to involve parents as equal partners.
The report also noted the low proportion of calls to the helpline from children and young people and suggested a separate helpline or closer liaison with Childline.
Both studies were carried out by teams led by Professor Sheila Riddell of Edinburgh University's Centre for Research in Education, Inclusion and Diversity.