The Financial Conduct Authority's business plan has failed to calculated the Dilnot cap correctly Kay Ingram, divisional director of LEBC Group has warned.
Ingram warned that the FCA's calculations took the cap to be £72,000, without taking into account costs which will not be met by the state.
The FCA's business plan notes the need to cater for the age of those who will have a long retirement and then face care fees at the end of their lives.
The Dilnot cap limits spending on care fees to £72,000, excluding costs incurred before April 2016, "hotel costs" and care fees which are in excess of the local authority's limit.
A survey found that 27% of consumers expected advice about their needs for long term care from the Pension Wise service.
Ingram said: "Unfortunately the FCA seems to believe that the Care Act will limit the cost of care per person to a cap of £72,000, after which all care costs will be met by the State.
"This is not the case and a detailed study of the provisions of the Care Act shows that in assessing the £72,000 private spending on care, it excludes a lot of the costs actually incurred.
"This means that many people may pay more than double the care cost cap, before the State and local authority step in to pick up the balance."
Ingram added: "All these factors are likely to mean that each person requiring care should budget for twice the care cap of £72,000 if they want to maintain choices about their care.
"If the Financial Services regulator does not understand the complexity of how the care cap is calculated, what hope have consumers, who do not have a regulated financial adviser to rely on, of understanding the need to fund for long term care beyond the headline £72,000?"
