The UK government has repeated its threat to legislate if businesses do not voluntarily release data gathered on customers who ask to see it.
An initiative called Midata calls on firms to provide details to the public in a "machine-readable" format.
Ministers had warned in August they would introduce a new law if utilities, web firms and shops did not voluntarily comply with their request.
Consumer Affairs Minister Jo Swinson will provide more details on Monday.
Under the existing Data Protection Act consumers already have the power to make a "subject access request" to see the personal information companies and other organisations hold on them.
But doing this can incur a fee of up to £10 and not all data has to be handed over.