Blind Year draft determinations

On 2 October 2025, we published our draft determination on the 2024-25 blind year reconciliation (BYR) where we set out how we propose to adjust companies’ price controls to account for the difference between: 

  • companies’ actual performance for 2024-25 on their PR19 reconciliation mechanisms and their forecast performance included in the PR24 final determinations; and  
  • the correction of unambiguous errors in the PR24 final determination.

Included within Appendix A1 of companies’ blind year draft determinations are our outcome delivery incentives (ODI) draft determinations for 2024-25. This sets out payments due to companies or customers as a result of the difference between: 

  • companies’ actual performance against their performance commitments in 2024-25; and 
  • forecast performance included in their PR24 final determinations.

The consultation on our draft determination will close at 5pm on Monday 20 October 2025.

Documents

Our draft determinations are set out in the main Sector Summary and the company-specific document for each water and wastewater company.

Company

Draft determination for consultation
Affinity Water  Affinity Water – Blind Year draft determination 2024-25
Anglian Water  Anglian Water – Blind Year draft determination 2024-25
Dwr Cymru  Dwr Cymru – Blind Year draft determination 2024-25
Hafren Dyfrdwy  Hafren Dyfrdwy – Blind Year draft determination 2024-25
Northumbrian Water  Northumbrian Water – Blind Year draft determination 2024-25
Portsmouth Water  Portsmouth Water – Blind Year draft determination 2024-25
SES Water  SES Water – Blind Year draft determination 2024-25
Severn Trent Water  Severn Trent Water – Blind Year draft determination 2024-25
South East Water  South East Water – Blind Year draft determination 2024-25
South Staffs Water  South Staffs Water– Blind Year draft determination 2024-25
South West Water  South West Water – Blind Year draft determination 2024-25 
Southern Water  Southern Water – Blind Year draft determination 2024-25
Thames Water  Thames Water – Blind Year draft determination 2024-25
United Utilities  United Utilities – Blind Year draft determination 2024-25
Wessex Water  Wessex Water – Blind Year draft determination 2024-25
Yorkshire Water  Yorkshire Water – Blind Year draft determination 2024-25

Price control deliverables (PCDs)

Alongside our draft determinations, we publish an updated version of our PR19 ODI PCDs (republished on 13 November 2025 with blind year ODI final determinations).

Models

The blind year reconciliation uses a suite of models, which reflect the reconciliation mechanisms put in place for the 2020-25 control period. Below we’ve set out the models we have used to set the draft determination.  

For optimal viewing, please download and open files using Microsoft Excel rather than in your web browser.   

Company specific models

Company

Error difference model 

ODI performance for 2024-25

ODI BYR difference

Wholesale Revenue Forecasting Incentive (RFI)

Residential retail reconciliation

Developer services revenue adjustment mechanism

Cost of new debt reconciliation

Land sales

RPI-CPIH wedge

Cost sharing reconciliation

RCV adjustments feeder model

Revenue adjustments feeder model

BYR adjustments

2024-25 In-period adjustments model

Transition and Accelerated programmes
Affinity Water Error difference model – Affinity Water ODI performance for 2024-25 – Affinity Water ODI BYR difference – Affinity Water Wholesale Revenue Forecasting Incentive – Affinity Water Residential retail reconciliation – Affinity Water Developer services revenue adjustment mechanism – Affinity Water Cost of new debt reconciliation – Affinity Water Land sales – Affinity Water RPI-CPIH wedge – Affinity Water Cost sharing reconciliation – Affinity Water RCV adjustments feeder model – Affinity Water  Revenue adjustments feeder model – Affinity Water BYR adjustments – Affinity Water 2024-25 In-period adjustments model – Affinity Water Transition and Accelerated programmes – Affinity Water
Anglian Water Error difference model – Anglian Water ODI performance for 2024-25 – Anglian Water ODI BYR difference – Anglian Water Wholesale Revenue Forecasting Incentive -Anglian Water Residential retail reconciliation – Anglian Water Developer services revenue adjustment mechanism – Anglian Water Cost of new debt reconciliation – Anglian Water Land sales – Anglian Water RPI-CPIH wedge – Anglian Water Cost sharing reconciliation – Anglian Water RCV adjustments feeder model – Anglian Water Revenue adjustments feeder model – Anglian Water BYR adjustments – Anglian Water 2024-25 In-period adjustments model – Anglian Water Transition and Accelerated programmes – Anglian Water
Bristol Water Error difference model – Bristol Water ODI performance for 2024-25 – Bristol Water ODI BYR difference – Bristol Water Wholesale Revenue Forecasting Incentive – Bristol Water Residential retail reconciliation – Bristol Water Developer services revenue adjustment mechanism – Bristol Water Cost of new debt reconciliation – Bristol Water Land sales – Bristol Water RPI-CPIH wedge – Bristol Water Cost sharing reconciliation – Bristol Water RCV adjustments feeder model – Bristol Water Revenue adjustments feeder model – Bristol Water BYR adjustments – Bristol Water Transition and Accelerated programmes – Bristol Water
Dŵr Cymru Error difference model – Dŵr Cymru ODI performance for 2024-25 – Dŵr Cymru ODI BYR difference – Dŵr Cymru Wholesale Revenue Forecasting Incentive – Dŵr Cymru Residential retail reconciliation – Dŵr Cymru Developer services revenue adjustment mechanism – Dŵr Cymru Cost of new debt reconciliation – Dŵr Cymru Land sales – Dŵr Cymru RPI-CPIH wedge – Dŵr Cymru Cost sharing reconciliation – Dŵr Cymru RCV adjustments feeder model – Dŵr Cymru Revenue adjustments feeder model – Dŵr Cymru BYR adjustments – Dŵr Cymru 2024-25 In-period adjustments model – Dŵr Cymru
Hafren Dyfrdwy Error difference model – Hafren Dyfrdwy ODI performance for 2024-25 – Hafren Dyfrdwy ODI BYR difference – Hafren Dyfrdwy Wholesale Revenue Forecasting Incentive – Hafren Dyfrdwy Residential retail reconciliation – Hafren Dyfrdwy Developer services revenue adjustment mechanism – Hafren Dyfrdwy Cost of new debt reconciliation – Hafren Dyfrdwy Land sales – Hafren Dyfrdwy RPI-CPIH wedge – Hafren Dyfrdwy Cost sharing reconciliation – Hafren Dyfrdwy RCV adjustments feeder model – Hafren Dyfrdwy Revenue adjustments feeder model – Hafren Dyfrdwy BYR adjustments – Hafren Dyfrdwy 2024-25 In-period adjustments model – Hafren Dyfrdwy
Northumbrian Water Error difference model – Northumbrian Water ODI performance for 2024-25 – Northumbrian Water ODI BYR difference – Northumbrian Water Wholesale Revenue Forecasting Incentive – Northumbrian Water Residential retail reconciliation – Northumbrian Water Developer services revenue adjustment mechanism – Northumbrian Water Cost of new debt reconciliation – Northumbrian Water Land sales – Northumbrian Water RPI-CPIH wedge – Northumbrian Water Cost sharing reconciliation – Northumbrian Water RCV adjustments feeder model – Northumbrian Water Revenue adjustments feeder model – Northumbrian Water BYR adjustments – Northumbrian Water 2024-25 In-period adjustments model – Northumbrian Water Transition and Accelerated programmes – Northumbrian Water
Portsmouth Water Error difference model – Portsmouth Water ODI performance for 2024-25 – Portsmouth Water ODI BYR difference – Portsmouth Water Wholesale Revenue Forecasting Incentive – Portsmouth Water Residential retail reconciliation – Portsmouth Water Developer services revenue adjustment mechanism – Portsmouth Water Cost of new debt reconciliation – Portsmouth Water Land sales – Portsmouth Water RPI-CPIH wedge – Portsmouth Water Cost sharing reconciliation – Portsmouth Water RCV adjustments feeder model – Portsmouth Water Revenue adjustments feeder model – Portsmouth Water BYR adjustments – Portsmouth Water 2024-25 In-period adjustments model – Portsmouth Water Transition and Accelerated programmes – Portsmouth Water
SES Water Error difference model – SES Water ODI performance for 2024-25 – SES Water ODI BYR difference – SES Water Wholesale Revenue Forecasting Incentive – SES Water Residential retail reconciliation – SES Water Developer services revenue adjustment mechanism – SES Water Cost of new debt reconciliation – SES Water Land sales – SES Water RPI-CPIH wedge – SES Water Cost sharing reconciliation – SES Water RCV adjustments feeder model – SES Water Revenue adjustments feeder model – SES Water BYR adjustments – SES Water 2024-25 In-period adjustments model – SES Water
Severn Trent Water Error difference model – Severn Trent Water ODI performance for 2024-25 – Severn Trent Water ODI BYR difference – Severn Trent Water Wholesale Revenue Forecasting Incentive – Severn Trent Water Residential retail reconciliation – Severn Trent Water Developer services revenue adjustment mechanism – Severn Trent Water Cost of new debt reconciliation – Severn Trent Water Land sales – Severn Trent Water RPI-CPIH wedge – Severn Trent Water Cost sharing reconciliation – Severn Trent Water RCV adjustments feeder model – Severn Trent Water Revenue adjustments feeder model – Severn Trent Water BYR adjustments – Severn Trent Water 2024-25 In-period adjustments model – Severn Trent Water Transition and Accelerated programmes – Severn Trent Water
South East Water Error difference model – South East Water ODI performance for 2024-25 – South East Water ODI BYR difference – South East Water Wholesale Revenue Forecasting Incentive – South East Water Residential retail reconciliation – South East Water Developer services revenue adjustment mechanism – South East Water Cost of new debt reconciliation – South East Water Land sales – South East Water RPI-CPIH wedge – South East Water Cost sharing reconciliation – South East Water RCV adjustments feeder model – South East Water Revenue adjustments feeder model – South East Water BYR adjustments – South East Water 2024-25 In-period adjustments model – South East Water Transition and Accelerated programmes – South East Water
South Staffs Water Error difference model – South Staffs Water ODI performance for 2024-25 – South Staffs Water ODI BYR difference – South Staffs Water Wholesale Revenue Forecasting Incentive – South Staffs Water Residential retail reconciliation – South Staffs Water Developer services revenue adjustment mechanism – South Staffs Water Cost of new debt reconciliation – South Staffs Water Land sales – South Staffs Water RPI-CPIH wedge – South Staffs Water Cost sharing reconciliation – South Staffs Water RCV adjustments feeder model – South Staffs Water Revenue adjustments feeder model – South Staffs Water BYR adjustments – South Staffs Water 2024-25 In-period adjustments model – South Staffs Water Transition and Accelerated programmes – South Staffs Water
South West and Bristol Water Error difference model – South West and Bristol Water
South West Water Error difference model – South West Water ODI performance for 2024-25 – South West Water ODI BYR difference – South West Water Wholesale Revenue Forecasting Incentive – South West Water Residential retail reconciliation – South West Water Developer services revenue adjustment mechanism – South West Water Cost of new debt reconciliation – South West Water  Land sales – South West Water RPI-CPIH wedge – South West Water Cost sharing reconciliation – South West Water RCV adjustments feeder model – South West Water Revenue adjustments feeder model – South West Water BYR adjustments – South West Water 2024-25 In-period adjustments model – South West Water Transition and Accelerated programmes – South West Water
Southern Water Error difference model – Southern Water ODI performance for 2024-25 – Southern Water ODI BYR difference – Southern Water Wholesale Revenue Forecasting Incentive – Southern Water Residential retail reconciliation – Southern Water Developer services revenue adjustment mechanism – Southern Water Cost of new debt reconciliation – Southern Water Land sales – Southern Water RPI-CPIH wedge – Southern Water Cost sharing reconciliation – Southern Water RCV adjustments feeder model – Southern Water Revenue adjustments feeder model – Southern Water BYR adjustments – Southern Water 2024-25 In-period adjustments model – Southern Water Transition and Accelerated programmes – Southern Water
Thames Water Error difference model – Thames Water ODI performance for 2024-25 – Thames Water ODI BYR difference – Thames Water Wholesale Revenue Forecasting Incentive – Thames Water Residential retail reconciliation – Thames Water Developer services revenue adjustment mechanism – Thames Water Cost of new debt reconciliation – Thames Water Land sales – Thames Water RPI-CPIH wedge – Thames Water Cost sharing reconciliation – Thames Water RCV adjustments feeder model – Thames Water Revenue adjustments feeder model – Thames Water BYR adjustments – Thames Water 2024-25 In-period adjustments model – Thames Water
United Utilities Error difference model – United Utilities ODI performance for 2024-25 – United Utilities ODI BYR difference – United Utilities Wholesale Revenue Forecasting Incentive – United Utilities Residential retail reconciliation – United Utilities Developer services revenue adjustment mechanism – United Utilities Cost of new debt reconciliation – United Utilities Land sales – United Utilities RPI-CPIH wedge – United Utilities Cost sharing reconciliation – United Utilities RCV adjustments feeder model – United Utilities Revenue adjustments feeder model – United Utilities BYR adjustments – United Utilities 2024-25 In-period adjustments model – United Utilities Transition and Accelerated programmes – United Utilities
Wessex Water Error difference model – Wessex Water ODI performance for 2024-25 – Wessex Water ODI BYR difference – Wessex Water Wholesale Revenue Forecasting Incentive – Wessex Water Residential retail reconciliation – Wessex Water Developer services revenue adjustment mechanism – Wessex Water Cost of new debt reconciliation – Wessex Water Land sales – Wessex Water RPI-CPIH wedge – Wessex Water Cost sharing reconciliation – Wessex Water RCV adjustments feeder model – Wessex Water Revenue adjustments feeder model – Wessex Water BYR adjustments – Wessex Water 2024-25 In-period adjustments model – Wessex Water Transition and Accelerated programmes – Wessex Water
Yorkshire Water Error difference model – Yorkshire Water ODI performance for 2024-25 – Yorkshire Water ODI BYR difference – Yorkshire Water Wholesale Revenue Forecasting Incentive – Yorkshire Water Residential retail reconciliation – Yorkshire Water Developer services revenue adjustment mechanism – Yorkshire Water Cost of new debt reconciliation – Yorkshire Water Land sales – Yorkshire Water RPI-CPIH wedge – Yorkshire Water Cost sharing reconciliation – Yorkshire Water RCV adjustments feeder model – Yorkshire Water Revenue adjustments feeder model – Yorkshire Water BYR adjustments – Yorkshire Water 2024-25 In-period adjustments model – Yorkshire Water Transition and Accelerated programmes – Yorkshire Water

 

Company

Tax reconciliation

Bioresources revenue reconciliation

Strategic regional water resources reconciliation

Green recovery cost allowance adjustment

Green recovery time value of money (TVM) adjustment

Business Retail

 

Other adjustments

 

Water trading incentives

 
Affinity Water Tax reconciliation – Affinity Water Strategic regional water resources reconciliation – Affinity Water Water trading incentives – Affinity Water
Anglian Water Bioresources revenue reconciliation – Anglian Water Strategic regional water resources reconciliation – Anglian Water
Bristol Water Tax reconciliation – Bristol Water Strategic regional water resources reconciliation – Bristol Water
Dŵr Cymru Bioresources revenue reconciliation – Dŵr Cymru Business Retail – Dŵr Cymru
Hafren Dyfrdwy Tax reconciliation – Hafren Dyfrdwy Bioresources revenue reconciliation – Hafren Dyfrdwy Business Retail – Hafren Dyfrdwy
Northumbrian Water Tax reconciliation – Northumbrian Water Bioresources revenue reconciliation – Northumbrian Water
Portsmouth Water Tax reconciliation – Portsmouth Water Other adjustments – Portsmouth Water
SES Water Tax reconciliation – SES Water
Severn Trent Water Tax reconciliation – Severn Trent Water Bioresources revenue reconciliation – Severn Trent Water Strategic regional water resources reconciliation – Severn Trent Water Green recovery cost allowance adjustment – Severn Trent Water Green recovery time value of money (TVM) adjustment – Severn Trent Water
South East Water Tax reconciliation – South East Water
South Staffs Water Tax reconciliation – South Staffs Water Strategic regional water resources reconciliation – South Staffs Water Green recovery cost allowance adjustment – South Staffs Water Green recovery time value of money (TVM) adjustment – South Staffs Water Other adjustments – South Staffs Water
South West and Bristol Water
South West Water Tax reconciliation – South West Water Bioresources revenue reconciliation – South West Water Strategic regional water resources reconciliation – South West Water Green recovery cost allowance adjustment – South West Water Green recovery time value of money (TVM) adjustment – South West Water Other adjustments – South West Water
Southern Water Bioresources revenue reconciliation – Southern Water Strategic regional water resources reconciliation – Southern Water Water trading incentives – Southern Water
Thames Water Bioresources revenue reconciliation – Thames Water Strategic regional water resources reconciliation – Thames Water Water trading incentives – Thames Water
United Utilities Tax reconciliation – United Utilities Bioresources revenue reconciliation – United Utilities Strategic regional water resources reconciliation – United Utilities Green recovery cost allowance adjustment – United Utilities Green recovery time value of money (TVM) adjustment – United Utilities
Wessex Water Tax reconciliation – Wessex Water Bioresources revenue reconciliation – Wessex Water Strategic regional water resources reconciliation – Wessex Water
Yorkshire Water Bioresources revenue reconciliation – Yorkshire Water Strategic regional water resources reconciliation – Yorkshire Water

Sector models

C-MeX and D-MeX are financial and reputational incentive mechanisms designed to provide customers in the water sector with excellent levels of service. Each company can receive outperformance payments or incur underperformance payments based on how it scores compared to other companies. See C-MeX and D-MeX 2024-25 results for more information.

  • Tax loss surrender adjustment model – This model calculates the appropriate adjustment to the tax reconciliation model adjustments for any losses surrendered to a company’s wider group during the PR19 period. This model is to be read in conjunction with the Tax Reconciliation models published above.

PR24 cost assessment models

Updated models that have been adjusted in the blind year to correct for agreed unambiguous error. Individual enhancement feeder models are as previously published at Final determinations models.

Accounting for PR24 final determination errors

Our PR24 final determination included the option to account for unambiguous errors in allowed revenue within the blind year adjustment through the revenue forecasting incentive (RFI) formula. This is set out in section A3 of the Notification of the PR24 final determination of price controls letter sent to each company on 19 December 2024 and in IN25/01.

We confirmed to companies that we would retain the definition of unambiguous error we used for the 2019-20 blind year process (see page 6 of IN2006 Approach to PR19 Blind year adjustments for 2019-20).

In our draft determination models for the blind year reconciliation 2024-25, we have separately identified the blind year adjustments that relate to:

  • the difference between forecast and actual performance for 2024-25; and
  • the correction of unambiguous PR24 errors that do not relate to past delivery.

PR24 unambiguous errors were confirmed through the PR24 in-bound query process and recorded on the PR24 final determinations change log on our website.

On 27 August 2025 we shared a consolidated PR24 unambiguous errors’ log with companies. We asked companies to review the log for completeness and accuracy ahead of our draft determination for the blind year reconciliation 2024-25. Following companies’ feedback, on 3 October we published an updated PR24 unambiguous errors’ log containing the errors we have corrected for in our draft determination for the blind year reconciliation 2024-25.