Direct Answer
Assurance readiness is a documentation problem more often than a measurement problem. A reviewer takes a reported packaging figure and traces it back to source records, testing whether the controls that produced it operate consistently and whether the method behind it is defined and applied. For packaging, the numbers in scope are usually volume or weight placed on the market, recycled content, recyclability status and any packaging emissions figure. Readiness means four things: each metric defined with its boundary, method and owner; the control documented including review and approval; source records for the period held in one accessible location; and an internal dry-run completed on a sample of formats. Most findings in the first assurance cycle are documentation gaps, and a dry-run removes the majority of them before the reviewer arrives.
Opening Hook
A company reports a recycled content figure for two years, and at its first assurance review the provider asks to see the record behind one supplier's share. The team produces a spreadsheet, the supplier produces a summary email, and the two disagree by four percentage points because one was compiled at the start of the year and one at the end. The number was never wrong; it was never controlled. Assurance reviews do not look for perfect data, they look for a trail — a defined metric, a method, a control and a record. Companies that build that trail before the review spend days on it; companies that build it during the review spend months. At ecosora, we help brands assemble the packaging evidence file so assurance becomes a review rather than a rescue.
What the Reviewer Traces
The review follows a chain, and every link has to exist.
| Link | Question Asked | Document Expected |
|---|---|---|
| Reported metric | What exactly is reported? | Metric definition and boundary |
| Method | How is it calculated? | Method statement with factors |
| Source data | Where did the inputs come from? | Invoices, registers, supplier records |
| Control | Who checks and approves? | Review record with names and dates |
| Population | Does the sample represent it? | Full listing for the period |
| Restatement | What if the figure changes? | Policy for prior-period adjustment |
Two links are commonly missing. The control link is the one that turns a figure into an auditable process; a number assembled by one person with no second review is difficult to defend even when accurate. The population link is the one that determines whether sample testing means anything: a provider testing five formats needs a full listing to select from, and a company that can only produce the five files it prepared is signalling that the records are assembled for the review rather than maintained.
Data: ISO maintains standards on assurance engagements, environmental management and sustainability reporting that define how reported information is reviewed and how environmental data is controlled.
Judgment: Define each packaging metric to a recognised framework before the first review, because assurance tests the method as well as the number and an undefined metric cannot be tested.
Source: International Organization for Standardization — Assurance, Environmental and Reporting Standards (2024)
Building the Metric Definition That Survives Review
| Definition Element | Content | Common Weakness |
|---|---|---|
| Metric name | Precise statement of what is measured | Named loosely, read differently by teams |
| Boundary | Inclusions and exclusions | Not stated, changed silently |
| Unit and basis | Weight, volume, percentage basis | Basis varies between suppliers |
| Method | Standard or calculation approach | Named without version |
| Owner | Named accountable person | Role described, not assigned |
| Source system | Where inputs originate | Multiple, unreconciled sources |
The boundary and the unit basis do the heaviest lifting, because they are the two elements that change a number without anyone intending to mislead. Recycled content reported by weight for one supplier and by volume for another produces an aggregate that is neither. A packaging emissions figure computed cradle-to-gate for one format and cradle-to-grave for another cannot be summed. Fixing the definition once, in writing, and holding suppliers to it at the point of data collection is cheaper than reconciling divergent records later, and the reporting data set that these definitions feed is described in our guide to packaging sustainability reporting data.
Data: The European Commission's packaging and plastics policy sets the direction of EU rules on packaging data, recyclability and reuse that shape which packaging figures companies are expected to report.
Judgment: Align packaging metric definitions with the requirements the company will report against, because a metric defined only for internal use usually needs rebuilding when it becomes externally reported.
Source: European Commission — Packaging and Plastics Policy (2025)
Controls That Make Packaging Data Auditable
| Control | Purpose | Evidence |
|---|---|---|
| Data request template | Consistent supplier inputs | Issued request and responses |
| Reconciliation | Match supplier data to purchasing records | Reconciliation working file |
| Review and approval | Second-person check before reporting | Signed review record |
| Version control | Track changes and restatements | Register with version history |
| Access control | Limit who can alter the register | System permission record |
| Period close | Freeze the data for the reporting period | Dated close confirmation |
The control set is small and familiar; the difficulty is applying it to packaging data that originates in several places. Reconciliation is the control that most improves data quality, because it forces a comparison between what suppliers declare and what the company actually buys. Where the two disagree, the cause is usually a change of material, a change of supplier or a unit basis difference, and each of those is worth knowing regardless of the review. The supplier-side counterpart to this control, including how to request and verify the underlying declarations, is set out in our packaging supplier sustainability audit framework.
Data: The U.S. Federal Trade Commission publishes rules and guidance on environmental marketing claims that define the substantiation expectation for claims made to consumers.
Judgment: Keep reporting data and marketing claims traceable to the same evidence, because figures published in a report are frequently reused in claims where the substantiation standard is stricter.
Source: U.S. Federal Trade Commission — Truth in Advertising (2025)
Running the Internal Dry-Run
| Step | Activity | Output |
|---|---|---|
| 1. Select | Choose a sample across formats and markets | Sample list with rationale |
| 2. Trace | Follow each figure to source | Completed trail per sample |
| 3. Test control | Confirm review and approval occurred | Control evidence per sample |
| 4. Log gaps | Record missing documents | Findings log with owners |
| 5. Fix | Close documentation gaps | Updated files before review |
| 6. Brief | Prepare named contacts per topic | Reviewer contact list |
The dry-run is where most findings are prevented, and it takes days rather than weeks when the register already exists. Two preparation details matter on the day: name a contact for each topic so the reviewer is not routed through a single overloaded person, and confirm that the source records are accessible from the review location rather than trapped in a system the reviewer cannot reach. Both are administrative, and both are common causes of delay.
Data: TAPPI publishes technical resources on packaging materials and converting that define the material properties used to describe paper-based packaging consistently.
Judgment: Keep material definitions technical and stable across reporting periods, because a material figure that changes definition between years cannot be trended or assured.
Source: TAPPI — Packaging Materials and Converting Resources (2024)
Frequent First-Cycle Findings
| Finding | Root Cause | Prevention |
|---|---|---|
| Unit basis inconsistency | Suppliers answered different questions | Fixed template with defined units |
| Boundary change mid-year | Method edited without versioning | Version-controlled method statement |
| Missing approval record | Figures assembled by one person | Second-person review control |
| Supplier data unreconciled | Declared figures not compared to purchases | Periodic reconciliation |
| Incomplete population | Only prepared files available | Maintained register for all formats |
| Restatement without disclosure | Prior figures changed silently | Restatement policy and disclosure |
Most of these are process findings rather than accuracy findings, which is why companies that invest in a maintained register and a defined metric tend to pass with modest effort. The restatement row is worth particular attention: changing a prior-period figure without disclosing it undermines the credibility of the whole report, and a simple written policy prevents the error from being made in good faith.
The Bottom Line
Assurance readiness is a defined metric, a documented control, a maintained register and an internal dry-run — get the trail in place before the reviewer arrives, because most first-cycle findings are documentation gaps rather than wrong numbers.