The frameworks we use to define and measure social value shape how decisions are made across the public and voluntary sectors. Two of the most commonly used approaches in the UK are the TOMs™ framework and the Social Return on Investment (SROI) methodology. While both have the same goal — to demonstrate the value created beyond financial profit — they take very different paths to get there.
Understanding the two social value approaches
TOMs™, short for Themes, Outcomes, Measures, is a framework developed by a commercial organisation, the Social Value Portal. It’s widely used by local authorities to score public procurement bids. It assigns financial values to predefined activities such as local employment or volunteering hours, allowing buyers to compare bids based on their projected social value.
SROI, or Social Return on Investment, is a principles-based approach that seeks to understand the broader outcomes of an activity from the perspective of the people affected by it. It involves engaging stakeholders, mapping outcomes, and using transparent proxy values to estimate social return. The Social Value Engine platform supports organisations to apply this method in a clear, consistent and credible way.
How the TOMs™ work in practice
The TOMs work by assigning fixed financial values to specific actions. For example, an apprenticeship might be worth £14,000. If a bidder promises to create five apprenticeships, their social value score is £70,000. This total is then compared to the contract value and forms part of the bid evaluation, typically with a set weighting (e.g. 10%).
This approach is designed for consistency and speed. But its simplicity can come at a cost. The same financial value is applied regardless of local context — an apprenticeship in a remote village may be far more impactful than one in a city centre, but both are treated equally. And while the TOMs aim to reward additionality, it often overlooks the inherent value already delivered by mission-led organisations.
How SROI works in practice
SROI begins by identifying the stakeholders who are affected by a project or service and engaging with them to understand what changes occur as a result. These changes — or outcomes — are then mapped in a theory of change, showing how specific activities lead to meaningful results. Each outcome is assigned a financial value based on stakeholder input, allowing the overall social value to be calculated in monetary terms. Importantly, SROI also accounts for factors like attribution, deadweight, and displacement to ensure claims are fair and credible. The process is transparent, evidence-based, and rooted in stakeholder experience, making it particularly suitable for organisations that want to demonstrate impact in a way that’s both rigorous and human.
Comparing TOMs and SROI
| Aspect | TOMs™ (Themes, Outcomes, Measures) | SROI (Social Return on Investment) |
| Developer | Social Value Portal (commercial framework) | Global movement, endorsed by Social Value International |
| Primary Use | Scoring social value in procurement bids | Measuring meaningful change for stakeholders |
| Financial Proxies | Fixed, standardised, centrally defined | Open-source, adaptable, stakeholder-informed |
| Stakeholder Engagement | Not required | Essential to the process |
| Focus on Additionality | Yes – emphasis on what’s added beyond the core contract | Includes both additional and inherent social value |
| Regional Sensitivity | No – treats all actions the same regardless of context | Yes – allows local adaptation and nuance |
| Verification Mechanism | Limited – risk of non-delivery or inflated claims | Supports evidence, validation, and transparency |
| Use in Commissioning | Favoured in procurement scoring (esp. local government) | Strong fit for strategy, evaluation, and community services |
| Accessibility for VCSEs | Often cost-prohibitive and complex | Designed to be inclusive and mission-aligned |
Why the VCSE sector in particular is critical of the TOMs and in favour of using SROI
Over time, the TOMs™ framework has helped embed social value into public sector procurement. It has made the concept more visible and has given commissioners a structure for comparing bids. However, many in the voluntary and community sector feel that TOMs has now created more barriers than it removes.
One key issue is cost. TOMs is a commercial model that often ties councils into exclusive contracts with the Social Value Portal. Winning bidders may be required to pay a percentage of the contract value back to the platform. For smaller charities or social enterprises, this can make it difficult (or even impossible) to bid.
There are also concerns about fairness. Because the TOMs rely on fixed proxy values and standardised measures, it’s possible for organisations to game the system — maximising scores without delivering meaningful change. Crucially, TOMs does not require stakeholder involvement, nor does it reflect the value created simply by being a purpose-driven organisation.
SROI starts from a different place. Rather than beginning with a list of actions, it begins by asking: what changes as a result of this work, and for whom? It values both outcomes and context, allowing organisations to consider regional variations, stakeholder priorities, and less tangible forms of value, such as wellbeing, inclusion or independence.
How the Social Value Engine makes SROI easier
While SROI is a powerful methodology, it can be time-consuming to apply without support. The Social Value Engine is designed to streamline the process. It provides users with pre-curated and independently verified proxy values, aligned with open-source standards and accredited by Social Value International. These values come with built-in guidance on their application and are automatically deflated to reflect present-day value — reducing the need for manual adjustments.
By structuring the process around clear steps and removing technical barriers, the Social Value Engine makes it easier for organisations of all sizes to produce credible, consistent, and auditable SROI assessments.
Choosing the right approach for procurement
TOMs and SROI are not always mutually exclusive. In some procurement settings, TOMs may be a required part of the scoring process — for instance, if a local authority is tied into a multi-year contract with no possibility of early termination.. But that doesn’t mean it should be used in isolation. Increasingly, commissioners are recognising the importance of taking a more balanced view — combining quantitative scores with qualitative evidence, stakeholder engagement, and a clear plan for verification.
For example, a social value assessment might consider:
- The value claimed (e.g. via TOMs or SROI)
- The confidence in delivery (track record, method, alignment)
- The quality of stakeholder engagement
- The relevance to local needs
- The mechanisms for monitoring and reporting
Running SROI analysis alongside the TOMs, with the view of switching to SROI-based reporting when that becomes an option, will provide a more complete, holistic view of social value delivery from the onset.
Final thoughts
So, what’s the difference between TOMs and SROI?
The TOMs offer a quick way to attach a number to procurement promises. SROI digs deeper, asking what’s changed, for whom, and how we know. The most important difference, though, isn’t technical — it’s philosophical.
SROI puts people first. It recognises that value isn’t something we impose; it’s something we discover by listening, measuring thoughtfully, and committing to real impact. That’s the difference that matters.
