What do consultants cost for a Scope 3 baseline, every year?

Hiring consultants to produce your supplier emissions baseline works. The engagement ends, the deck is good, the number is defensible. Then the companies behind the number keep publishing, restating and changing method, and the engagement is over. This post prices doing it again every year.

The scenario, shared across this series and stated as our assumption rather than a sourced figure: a UK organisation with 10,000 suppliers in its accounts payable export, committed to Scope 3, reporting annually. The 10,000 is the purchase ledger rather than an engagement list: most teams actively engage a few hundred suppliers, but Scope 3 Category 1 brings the whole ledger into the inventory, so the whole ledger is what the baseline has to cover. The same logic applies to a portfolio of investee companies.

What do consultants publicly charge?

The Big Four do not post rate cards on their own websites, but Deloitte and PwC both publish full day rates on the UK government's Digital Marketplace as a condition of selling through the G-Cloud framework. From the G-Cloud 14 SFIA rate cards, 2024: Deloitte's development and implementation rates run £1,290 at level 4 and £1,650 at level 5, rising to £2,050 and above at level 7; PwC's published ranges reach £2,750 a day. Dell Technologies Services, on the same framework, publishes £1,568 for a consultant and £2,927 for a principal consultant. All exclude VAT, cover an eight-hour day, and are ceiling rates for government buyers; private sector engagements are negotiated and unpublished.

What does a repeat engagement cost each year?

Our worked estimate, with the assumptions stated so you can substitute your own. Assume the annual refresh needs one level 4 consultant and one level 5, for 60 working days each cycle: enough to re-source the disclosures that changed, re-map the factor set that was reissued, and decide what gets restated. At Deloitte's published rates that is £1,290 plus £1,650, times 60 days: £176,400 per reporting cycle, before VAT. The rates are published; the team shape and the 60 days are ours. A first-time baseline engagement is larger: the build version of this arithmetic, at £507,600 for a six-month team, is worked through on our build vs buy page.

Run it over three years and the repeat engagement passes £529,000, which is the comparison that matters, because year one is the only year a consultant option gets to look like a one-off.

What does the day rate not show?

Three costs that never appear on the invoice.

• The knowledge leaves. Why this trading name was matched to that parent, why a restated figure was or was not adopted, why one factor set was chosen over another: those judgements live with the people who made them, and they roll off at the end of the engagement. Next year's team reconstructs or overrides them, and either way you pay for the decision twice.
• Method consistency is nobody's job. The GHG Protocol Corporate Standard obliges base year recalculation for changes in calculation methodology or improvements in the accuracy of emission factors or activity data that have a significant impact. A rotating team changing approach between cycles walks straight into that clause. The Science Based Targets initiative's survey with BCG, February 2023, from 230 organisations, found 70% had re-baselined in five years, half of those, so 35% of all respondents, for methodological reasons.
• The restatement lands on you. When the method does change, the revised disclosure, the analyst time and the conversation with whoever signed last year's number are yours, not the consultancy's. The engagement letter ended in March.

When are consultants the right answer?

For the parts that are genuinely one-off. Designing a methodology that is proprietary to your sector, running a gap analysis before a reporting obligation lands, or standing up governance around a programme: those are projects, they end, and a day rate is the honest way to buy them. What does not suit a day rate is the recurring half, the annual re-sourcing, re-mapping and restating, because it never ends and the rate never falls.

What is the alternative to buying the same project every year?

Buying the recurring half as a product. DitchCarbon provides verified emissions data for over 2 million organisations, so procurement, sustainability and finance teams can measure and act on supply chain and portfolio emissions from one source, with continuous refresh and documented sources, and every figure carrying its source and change history. The judgement calls a consultant team would rebuild each cycle are recorded in the data itself, which is why the second year costs the same as the first rather than starting again. Where the method does move, it arrives with its evidence: the Portal calculator is verified to ISO 14064-3, limited assurance, by UL Solutions, renewed annually.

If you are partway through this decision, request a walkthrough and put the published day rates next to it.

This post is part of a series pricing the alternatives to buying supplier emissions data, all on one shared scenario: collecting it manually, the spend-based minimum, doing nothing, and building the platform in house.

Last reviewed August 2026.