The BSA responded to the HMRC consultation "Better Use of New and Improved Third-Party Data to Make It Easier to Pay Tax Right Time" on 21 May 2025 which you can find here. 

To summarise, the BSA response is as follows:

• We understand and appreciate HMRC's work of helping taxpayers get their tax right the first time by pre-populating tax returns
• We state that moving to monthly reporting of financial account information, gathering of national insurance numbers and more timely reporting at the end of the reporting period will cause significant burdens and costs for all financial institutions, but will be disproportionately felt by smaller financial institutions like many of our members. 
• We ask that the schema, systems and requirements are harmonised where possible with existing systems, such as Cash ISA reporting. This step should simplify the reporting frameworks and allow for financial account reporting to be an extension of existing systems rather than creating entirely new systems.
• The collection and repeated requesting of national insurance numbers for existing accounts will be burdensome and ineffective without a significant HMRC communications project to stress to all taxpayers the importance of providing this data, and we request a separate transition period to allow for the collection of national insurance numbers for existing depositors.
• Additionally, without a government database to assess the accuracy of national insurance numbers for each depositor, financial institutions' verification must only be limited to checking that it is in the correct alphanumeric format