---
title: "Technical Advisor to the DESNZ Sizewell C team"
ocid: "ocds-b5fd17-279c9810-3c46-440e-b2cc-6109fbbb7402"
canonical_url: "https://d3tenders.com/contract/?ocid=ocds-b5fd17-279c9810-3c46-440e-b2cc-6109fbbb7402"
markdown_url: "https://d3tenders.com/contract/ocds-b5fd17-279c9810-3c46-440e-b2cc-6109fbbb7402.md"
json_url: "https://d3tenders.com/contract/ocds-b5fd17-279c9810-3c46-440e-b2cc-6109fbbb7402.json"
source: "Contracts Finder"
current_stage: "Award"
buyer: "DESNZ"
published: "2025-12-18"
---

# Technical Advisor to the DESNZ Sizewell C team

Buyer: DESNZ  
Current stage: Award  
OCID: ocds-b5fd17-279c9810-3c46-440e-b2cc-6109fbbb7402

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## Summary

The Department for Energy Security and Net Zero (DESNZ) has awarded a contract for technical advisory services related to the Sizewell C project. The award has been given to Mott MacDonald Limited, a large consultancy firm. This contract, assessed under CPV classification 71621000 for technical analysis or consultancy services, is focused on the oversight of the Sizewell C project during its post-Final Investment Decision and Financial Close phases. The procurement method used was a selective call-off from a framework agreement, and the contract period began on 1st December 2025 and will end on 30th November 2028. This contract has been valued at £4,840,000, with an award of £3,640,000. Although this tender is completed, it highlighted DESNZ's commitment to engaging specialised services for strategic energy projects.

The technical advisory contract for the Sizewell C project presents avenues for businesses that specialise in consultancy and technical analysis within the energy sector to showcase their expertise in large-scale infrastructure projects. This opportunity is particularly suited for large firms capable of delivering comprehensive and specialised services for significant energy projects. As the advisory services are aimed at supporting government roles in shareholder and policy sponsor capacities, businesses with experience in governmental and regulatory environments will find enhanced prospects for growth and increased visibility as key players in national energy initiatives. Additionally, this project encompasses a broad geographic scope, including the UK and various international locations, demonstrating the potential for cross-border cooperation and influence.

## Notice

The Department for Energy Security and Net Zero has awarded this Contract for the supply of Technical Advisory Services in respect of the Sizewell C project. The Supplier will support HMG in its oversight as Shareholder and Policy Sponsor of the Sizewell C Project in the post-Final Investment Decision and Financial Close phases of the project.

## Key Details

| Field | Value |
| --- | --- |
| Publication source | Contracts Finder |
| Latest notice | https://www.contractsfinder.service.gov.uk/Notice/053a7637-19ba-4255-aaed-e1699cdf54ed |
| Notice type | Award Notice |
| Procurement type | Framework |
| Procurement category | Services |
| Procurement method | Selective |
| Procurement method details | Call-off from a framework agreement |
| Tender suitability | Not specified |
| Awardee scale | Large |
| All stages | Award |

## Dates

| Field | Value |
| --- | --- |
| Publication date | 18 Dec 2025 |
| Submission deadline | 7 Oct 2025 |
| Future notice date | Not specified |
| Award date | 1 Dec 2025 |
| Contract period | 1 Dec 2025 - 30 Nov 2028 |
| Recurrence | Not specified |

## Values

| Field | Value |
| --- | --- |
| Tender value | £4,840,000 |
| Lots value | Not specified |
| Awards value | £3,640,000 |
| Contracts value | Not specified |

## Status

| Field | Value |
| --- | --- |
| Tender status | Complete |
| Lots status | Not specified |
| Awards status | Active |
| Contracts status | Not specified |

## Buyer

| Field | Value |
| --- | --- |
| Main buyer | DESNZ |
| Locality | LONDON |
| Post town | South West London |
| Postcode | SW1A 2AW |
| Country | England |
| ITL 1 | TLI London |
| ITL 2 | TLI3 Inner London - West |
| ITL 3 | TLI35 Westminster and City of London |
| Local authority | Westminster |
| Electoral ward | St James's |
| Westminster constituency | Cities of London and Westminster |
| Delivery location | Not specified |

## Supplier

| Field | Value |
| --- | --- |
| Number of suppliers | 1 |
| Supplier names | MOTT MACDONALD |

## CPV Codes

### Divisions

- 71 - Architectural, construction, engineering and inspection services

### Codes

- 71621000 - Technical analysis or consultancy services

## Release History

- 18 Dec 2025 at 16:38 - Award - Award Notice - https://www.contractsfinder.service.gov.uk/Notice/053a7637-19ba-4255-aaed-e1699cdf54ed

## Documents

- https://www.contractsfinder.service.gov.uk/Notice/053a7637-19ba-4255-aaed-e1699cdf54ed
  18th December 2025 - Awarded contract notice on Contracts Finder
- https://www.contractsfinder.service.gov.uk/Notice/Attachment/21c77a33-b34b-4b81-a755-bdea1463c377
  n/a
- https://beisgroup.ukp.app.jaggaer.com/esop/ect/filesharing/flist/9328577/0/foldersFilesList.si?reset=true&isOnModification=false&_ncp=1766075547057.861969-2#fh
  Contract

## Provenance

This Markdown file is an alternate public rendering of the D3 Tenders contract record. The canonical page is https://d3tenders.com/contract/?ocid=ocds-b5fd17-279c9810-3c46-440e-b2cc-6109fbbb7402. The underlying structured data is available as OCDS JSON at https://d3tenders.com/contract/ocds-b5fd17-279c9810-3c46-440e-b2cc-6109fbbb7402.json.