Low supplier response rates on Scope 3? How to keep your data growing

Most supplier engagement programmes reach a point where another round of reminders brings in almost nothing new. The suppliers who were going to reply have replied. Low supplier response rates on Scope 3 are normal at that stage. The way forward is to build on the data that already exists and ask suppliers for less.

Our guide to how automated software handles Scope 3 data gaps sets out what fills each line while you wait for replies.

Why do supplier response rates plateau?

Response rates plateau because the remaining suppliers can't answer, have already answered somewhere else, or see no reason to answer you. Each of those needs a different approach, and another reminder solves none of them.

Every customer sends its own questionnaire, in its own format and on its own deadline. At many suppliers the sustainability team is one or two people, often fitting the work around another job. Some have already published a GHG inventory or a product footprint and don't see why they should type it out again for each customer.

Security teams have lived with the same problem for years. In a 2020 survey of 154 third-party risk professionals by the Cyentia Institute and RiskRecon, only 14% said they were highly confident in the accuracy of vendor questionnaire responses. A questionnaire that comes back is not always one you can rely on, so chasing more of them only takes a programme so far.

What emissions data already exists for suppliers who haven't replied?

Usually more than the programme assumes. Many organisations on a typical supplier list have already published a GHG inventory, a product carbon footprint or a science-based target. That published data is primary emissions data in the GHG Protocol's terms, and a buyer can use it before sending a single request.

This is where DitchCarbon starts every programme: verified emissions data for over 2 million organisations, built on primary emissions data wherever it exists. That includes published GHG inventories and product carbon footprints, CDP responses, EcoVadis scorecards, SBTi targets and data that suppliers declare on their own profiles.

A supplier's own reported inventory, applied to what you spend with it, is supplier-specific (primary) emissions data. The data is the supplier's and the allocation to your spend is ours. Unlike a sector average, that figure moves when the supplier cuts its emissions. The guide to primary and spend-based data sets out the difference.

There is a second layer too. Activity and product data that suppliers have already provided through DitchCarbon for other clients, and agreed to share, is available to a new client from the start. Sharing is always the supplier's decision, and a disclosure made privately for one client stays with that client.

Together these layers carry a lot of a programme before anyone is asked. A recent deployment reached 70% coverage of emissions with primary data within 2 weeks.

How do you get more data from the suppliers you still need?

Send a smaller, more specific request to the suppliers where better data changes the result. When a request arrives prepopulated with what the supplier has already disclosed, it only asks for what you need to reduce or report accurately. The supplier adds to its existing profile and doesn't start from a blank form.

What you ask for depends on the purpose:

• the electricity consumption and renewable share of the facility that serves you
• the activity data behind what you buy, such as tonnes, litres or kWh
• a product carbon footprint for a named item
• a decarbonisation plan, or a GHG inventory specific to your business

Prepopulated requests get higher response rates than a cold survey, because the ask is small and the supplier can see its own data already in place. A recent deployment gained additional primary data from 30% of over 40,000 recipients.

The same method works for 100 suppliers or for 10,000. Requests go out from one platform, and every reply type (an uploaded report, a facility's energy figures, a product footprint) lands on the same record. Supplier engagement shows how the request works from the buyer's side, and Supplier survey fatigue: how to make the emissions ask smaller covers how to keep it small.

What should you report while engagement continues?

Report the most accurate figure available for every line, and show which method produced it. A hybrid calculation does exactly this: it uses the most accurate method available for each purchase, and an industry factor only where nothing above it exists. DitchCarbon's method hierarchy, from most to least accurate:

1. A published product carbon footprint for the item bought
2. Activity or service data the supplier has disclosed, such as its electricity or fuel
3. Generic activity data, calculated on a published factor such as ecoinvent
4. The supplier's own reported inventory applied to your spend
5. Industry-level spend, used only where nothing above it exists, with the line saying so

Every figure shows which method produced it, and the share of the baseline still on an industry factor is shown as a number. That share is a better progress measure for an engagement programme than its response rate. You start with numbers you can defend within 2 weeks. As suppliers disclose, their lines move up the hierarchy and the share falls.

How do you move from collecting data to reducing emissions?

Use the data you already have to find where action moves the footprint most, then work with those suppliers where they are. A stalled response rate doesn't have to stall reductions.

Some suppliers are already decarbonising. For them, show the glide path they are on and how it helps you hit your target, then let them carry on without another questionnaire. Others need a plan. A reduction plan drawn from a peer that has already made the cut gives the conversation a starting point grounded in what the supplier's industry has actually achieved. For many of them, the electricity they buy is the quickest lever.

Timing matters as well. To fund reductions next year, you need to know this year what you want to do and what it will cost. Two Scope 3 programmes, two years on follows what happens to a team that waits for survey data before making that case.

DitchCarbon gives large organisations that starting point and the tools to act on it. The baseline is built on the primary data suppliers have already published, requests ask only for what is still needed, and each supplier gets a reduction plan drawn from a peer that has already made the cut.