How to Conduct a Packaging Waste Audit in 5 Steps

If you are an obligated producer under the UK's Extended Producer Responsibility (EPR) scheme, the data you submit to DEFRA's Registration, Packaging Data and Reporting (RPD) system is only as good as the audit trail behind it. And for most businesses, that trail starts with a packaging waste audit: a structured process for identifying, categorising, weighing, and documenting every piece of packaging you place on the market.

Done properly, a packaging waste audit does three things. First, it gives you the accurate weight and material data that DEFRA requires in your submission file. Second, it reveals opportunities to reduce fees by identifying components that could be redesigned for a better RAM rating. Third, it protects you from enforcement risk. DEFRA has the power to audit obligated producers, and businesses that cannot demonstrate how they derived their reported figures face penalties.

Yet despite these stakes, many producers treat the audit as an afterthought. They estimate weights from supplier spec sheets that are years out of date, classify materials based on assumptions rather than testing, and leave the whole process to the final week before a submission deadline. The result is inaccurate data, overpaid fees, and unnecessary compliance risk.

This guide sets out a practical, five-step methodology for conducting a packaging waste audit that is thorough enough to withstand scrutiny, efficient enough to repeat annually, and detailed enough to feed directly into your DEFRA RPD submission.

Why Packaging Waste Audits Matter More Than Ever

Before the reformed EPR scheme launched in April 2025, packaging data obligations were limited. Producers reported tonnage by material type under the old Packaging Waste Regulations, but the level of granularity was low. A single line entry for "plastic packaging" might cover dozens of different formats, polymers, and weights.

The reformed scheme changed this fundamentally. The RPD now requires component-level data: every individual packaging component must be reported with its material type, weight, packaging class (primary, secondary, shipment, or tertiary), and waste type (household or non-household). From the 2026-2027 compliance year onward, the RAM rating for each household component directly influences the fees you pay through fee modulation.

This means the accuracy of your audit data has direct financial consequences. An error of just a few grams per unit, multiplied across millions of units, can shift your reported tonnage by hundreds of kilograms and move your fee invoice by thousands of pounds. Getting the audit right is no longer optional due diligence. It is cost management.

The businesses that treat their packaging audit as a strategic exercise, rather than a box-ticking compliance task, consistently find they are paying less in EPR fees than their competitors on equivalent tonnage.

Step 1: Define Your Audit Scope

A packaging waste audit can be as narrow or as broad as your business requires, but it must start with a clear scope definition. Without boundaries, the process becomes unwieldy and delivers data that is difficult to action.

Determine what is in scope

Under UK EPR, you must report all packaging that you place on the UK market where you are the obligated party. This typically includes:

• Primary packaging – the packaging in direct contact with the product at the point of sale (e.g., a bottle, a wrapper, a tray)
• Secondary packaging – packaging used to group primary units together (e.g., a cardboard outer, a shrink-wrap multipack)
• Shipment packaging – packaging used to ship goods to the consumer in e-commerce (e.g., a mailing box, void fill, a poly mailer)
• Tertiary or transit packaging – packaging used for transportation and distribution (e.g., pallets, stretch wrap, edge protectors)

Your first decision is whether to audit all four classes in a single exercise or break them into separate phases. For businesses with complex product ranges, a phased approach is often more manageable. Start with primary packaging, which is typically the highest volume and most complex, then move to secondary and shipment packaging in a second phase.

Set boundaries by product line or site

If your business operates across multiple sites or product categories, consider scoping the audit by location or brand. A single-site audit for a bakery with forty SKUs is very different from a multi-site audit for a FMCG manufacturer with three thousand. Setting clear boundaries prevents scope creep and ensures the audit is completed within a realistic timeframe.

Step 2: Gather Your Packaging Data

With the scope defined, the next step is to collect the raw information you need for each packaging component. This is the most time-consuming part of the audit, but it is also where the value lies. Accurate data gathered here flows directly into your DEFRA submission file and your RAM assessments.

Sources of packaging data

There are four primary sources of packaging data, and a robust audit typically draws from all of them:

1. Physical samples. The most reliable source. Collect actual samples of every packaging component used across your product range. This means not just the bottle or the box, but also the label, the cap, the liner, the seal, the insert, and any other separable component.
2. Supplier specification sheets. Packaging suppliers provide technical data sheets that include material composition, dimensions, and nominal weights. These are useful as a starting point, but they often reflect design specifications rather than actual production weights, which can differ by 5-15%.
3. Purchase records and invoices. Your procurement team can provide data on the volume and type of packaging purchased over a given period. This helps cross-check the tonnage figures derived from unit weights and sales volumes.
4. Product and sales data. Your ERP or sales system tells you how many units of each product were sold in the compliance period. Multiplying unit counts by per-component weights gives you the total tonnage placed on the market.

Building a component inventory

For each product SKU in your audit scope, break the packaging down into its individual components. A typical product might have five or more distinct packaging components:

This level of granularity is exactly what the RPD requires. Each row in the table above becomes a separate line in your DEFRA submission. Skipping components, especially small ones like labels and seals, is one of the most common audit errors and can result in understated tonnage that triggers a compliance query.

Step 3: Classify Materials Correctly

Material classification is where many audits go wrong. The RPD uses specific material categories defined by DEFRA, and these do not always align neatly with the material names used by packaging suppliers or in everyday industry language.

DEFRA material categories

The RPD requires you to classify each component into one of the following material types:

• Aluminium – including foil trays, cans, and closures
• Fibre composite – e.g., beverage cartons (Tetra Pak style), Pringles-type tubes
• Glass – bottles and jars
• Paper/card – corrugated board, folding boxboard, paper wraps, tissue paper
• Plastic – further broken down by polymer type for RAM assessment purposes
• Steel – cans, closures, and strapping
• Wood – pallets, crates
• Other – materials that do not fit into the above categories

Common classification mistakes

Based on audits we have seen across hundreds of producers, these are the most frequent material classification errors:

• Metallised films classified as aluminium. A metallised PP or PET film has a microscopically thin aluminium layer but is functionally a plastic. It should be classified as plastic, not aluminium. Getting this wrong changes both the base fee rate and the RAM assessment.
• Fibre composites classified as paper/card. A drinks carton with a polyethylene liner is a fibre composite, not paper/card. The distinction matters because fibre composites have different recycling pathways and RAM profiles.
• Laminated materials defaulting to "other." Multi-layer structures should be classified by their predominant material by weight. A laminate that is 70% paper and 30% plastic is classified as paper/card, not "other."
• Ignoring polymer type within plastics. While the RPD material category is simply "plastic," your RAM assessment requires the specific polymer (PET, HDPE, PP, LDPE, PS, PVC). Recording the polymer type during the audit saves significant rework later.

Step 4: Weigh Everything (Properly)

Weight data is the backbone of your EPR fee calculation. Every gram matters when multiplied across your annual production volumes. Yet weighing packaging components is more nuanced than it appears, and sloppy measurement practices are one of the biggest sources of data error in RPD submissions.

Equipment requirements

You need a precision scale capable of measuring to at least 0.1 grams for small components (labels, closures, seals) and a larger scale with 1-gram resolution for heavier items (corrugated outers, glass bottles). Using a kitchen scale that measures in 5-gram increments is not sufficient for compliance-quality data.

Weighing methodology

For each packaging component, follow this protocol:

1. Weigh at least three samples of the same component drawn from different production batches. Weight variation between batches is common, particularly for injection-moulded plastics and blown bottles where process parameters fluctuate.
2. Record the average weight across your samples. This average becomes the per-unit weight you use for tonnage calculations.
3. Weigh components dry and empty. Product residue, moisture, or adhesive from labels that have been peeled can all distort measurements. If you are weighing a used sample, clean it first.
4. Separate multi-component assemblies. A bottle with a cap is two components. Weigh them individually. A corrugated box with a plastic window is two components. Separate them before weighing.
5. Document everything. Record the date, the product SKU, the component description, the individual sample weights, and the calculated average. Photograph the component on the scale if practical. This documentation is your audit trail if DEFRA requests evidence.

Calculating total tonnage

Once you have per-unit weights for every component, the tonnage calculation is straightforward:

Total tonnage = per-unit component weight (kg) x number of units placed on the UK market in the compliance period

Your sales data or production records provide the unit counts. Be precise about the period. The EPR compliance year runs April to March, not January to December. Using calendar year sales figures without adjusting for the compliance period is another common mistake.

Notice that the corrugated outer, despite being a single component, represents nearly half the total tonnage in this example. This is typical. Transit and secondary packaging often outweigh primary packaging by a significant margin. Missing a transit component from your audit can cause a large tonnage gap in your submission.

Step 5: Analyse, Report, and Act on the Findings

The audit is not complete when the weighing is done. The final step is to transform your raw data into actionable intelligence: a dataset ready for DEFRA submission, a clear picture of your fee exposure, and a prioritised list of packaging changes that could reduce your costs.

Mapping data to the DEFRA RPD format

The RPD submission file is a structured CSV with 15 columns. Your audit data needs to map cleanly into this format. The key fields are:

• Organisation ID and subsidiary ID – your registered identifiers
• Brand – the brand under which the packaging is placed on the market
• Packaging class – primary, secondary, shipment, or transit
• Packaging type – the functional description (bottle, tray, box, film, etc.)
• Material type and sub-type – from your classification in Step 3
• Weight (tonnes) – from your calculations in Step 4
• Waste type – household or non-household
• RAM rating – Red, Amber, or Green (for household packaging)

Errors in format, missing fields, or inconsistent material codes will cause your submission to be rejected by the RPD system. Validating the file before upload saves time and avoids the stress of last-minute resubmission.

Analysing your fee exposure

With your complete dataset, you can now model your fee exposure under the current and future modulation multipliers. Group your tonnage by RAM rating to see the split:

• What percentage of your total household packaging tonnage is Green-rated?
• What percentage is Red-rated, and what is the associated fee premium?
• Which specific components are driving the most Red-rated tonnage?

This analysis directly informs your packaging optimisation strategy. The components that appear at the top of your Red-rated tonnage list are the ones to prioritise for material changes, because they represent the largest fee savings when moved to Amber or Green.

Using audit findings to reduce fees

A thorough audit almost always reveals opportunities. Common findings include:

• Over-specified packaging. Components that are heavier than they need to be. Lightweighting a bottle by even 2 grams, across millions of units, reduces your reported tonnage and your fees.
• Unnecessary components. Audit participants frequently discover packaging elements that exist for historical reasons but add no value, such as inner tissue paper in a box that already has a moulded insert, or double shrink-wrap layers on pallets.
• Easy material swaps. Replacing a carbon black tray with a detectable dark-coloured alternative moves the component from Red to Green with minimal supply chain disruption.
• Label material mismatches. Full-sleeve shrink labels on PET bottles can cause sortation failures. Switching to a smaller spot label or a compatible polymer can improve the bottle's RAM rating.

Common Audit Mistakes to Avoid

Having reviewed hundreds of packaging audits across businesses of all sizes, we consistently see the same errors. Avoid these and you will be ahead of most producers:

1. Relying solely on supplier specs. Nominal weights on spec sheets can be 5-15% different from actual production weights. Always verify with physical samples.
2. Forgetting small components. Caps, seals, labels, and inserts may weigh only a few grams each, but across high-volume product lines they add up to significant tonnage. A 2-gram label on 10 million units is 20 tonnes.
3. Using calendar year sales data. The EPR compliance year runs April to March. Using January-to-December figures without adjustment will misstate your tonnage for the compliance period.
4. Not separating household from non-household. RAM ratings and fee modulation only apply to household packaging. Misclassifying commercial or industrial packaging as household inflates your modulated fee exposure.
5. Conducting the audit once and never updating. Packaging changes throughout the year as you introduce new products, update designs, or switch suppliers. Build in quarterly reviews to keep your data current.
6. Not documenting methodology. If DEFRA audits your submission, they will ask how you derived your figures. Without documented methodology, sample photographs, and weighing records, you have no defence.

Building a Repeatable Audit Process

The first audit is always the hardest. It requires setting up processes, identifying data sources, and training team members. But the effort pays dividends in subsequent years, because a well-designed first audit becomes a template.

Here are practical recommendations for making your audit process sustainable:

• Centralise your packaging register. Maintain a living document or database that lists every packaging component, its material, weight, and RAM rating. Update it whenever packaging changes occur, not just at audit time.
• Integrate with procurement. When a new packaging component is onboarded, add it to the register immediately. Require suppliers to provide material composition data as a condition of purchase.
• Assign clear ownership. The audit needs an owner, typically someone in sustainability, compliance, or operations. Without a named responsible person, it becomes everyone's problem and no one's priority.
• Use consistent tools. Standardise on a single system for storing and managing your packaging data. Spreadsheets work for small portfolios, but they quickly become error-prone at scale. Purpose-built compliance platforms eliminate formatting errors and provide automatic validation against the RPD schema.

The producers who invest in a repeatable audit process find that the exercise takes less time each year, produces more accurate data, and consistently identifies cost-saving opportunities that one-off audits miss.

From Audit to Action

A packaging waste audit is not an end in itself. It is the foundation for every other compliance and cost-optimisation activity your business undertakes under EPR. Your DEFRA submission accuracy depends on it. Your RAM ratings are derived from it. Your fee modulation exposure is calculated from it. And your packaging improvement roadmap is prioritised by it.

The five steps outlined in this guide, scope definition, data gathering, material classification, weight measurement, and analysis, form a methodology that any obligated producer can follow. The key is to approach the audit with the rigour it deserves, invest in accurate measurement, document your methodology, and use the findings to drive real packaging improvements.

The businesses that do this well do not just comply with EPR. They turn compliance into competitive advantage.