The Financial Services Authority (FSA) has not received professional standards data from 15% of adviser firms, meaning they are in breach of regulatory rules.
Firms had until 29 January to submit details of each adviser's qualifications and accredited body membership.
An FSA spokeswoman urged the ‘significant minority’ of firms to send in their information.
‘We would like to encourage firms to provide this data, as by not providing this they are in breach of our rules,' she said.
She added that the number of Statements of Professional Standing (SPS) from accredited bodies currently did not match up to the data received from firms, meaning there are firms with qualified advisers that have not submitted data.
‘They’ve spent time and money getting their qualifications. They should want us to know about it,' she said.
The FSA sent reminders on 9 January requesting professional standards and complaints data for each adviser to be submitted by 29 January.
A systems failure at the FSA resulted in the regulator having to reissue the reminder letters after firms receive letters which quoted incorrect firm names and reference numbers.
The spokeswoman added that the regulator had posted a Q&A on its website with visual aids to help advisers submit the data.
She said if firms were having trouble submitting the data they needed to get in touch with the regulator as soon as possible.