Growing demand for supply chain visibility has created a need for traceable Better Cotton. New physical chain of custody models will be available from October 2023. Learn more about transitioning to the new Chain of Custody Standard, and the physical chain of custody models.

The Better Cotton Chain of Custody is the key framework that connects Better Cotton supply with demand

From the farmers who grow Better Cotton to the companies that source it, the Better Cotton Chain of Custody (CoC) is the documentation and evidence of Better Cotton as it moves through the supply chain. It ensures that the volume of Better Cotton claimed by Better Cotton Retailer and Brand Members does not exceed the volume of Better Cotton produced by licensed Better Cotton Farmers in any given time period.

What is a Chain of Custody?

In its Chain of custody models and definitions guide, ISEAL defines a chain of custody as: The custodial sequence that occurs as ownership or control of the material supply is transferred from one custodian to another in the supply chain.

Chain of Custody Models: our current Chain of Custody Guidelines

The current Better Cotton CoC Guidelines incorporate two different chain of custody models: product segregation between the farm and gin and mass balance beyond the gin.

Product Segregation Model

Between the farm and the gin, the Better Cotton Standard System requires a product segregation chain of custody model. This means that farmers and ginners need to store, transport and process Better Cotton (seed cotton and lint cotton bales) separately from any conventional cotton.

This ensures that all Better Cotton bales produced by participating gins are 100% Better Cotton and can be traced back to licensed Better Cotton Farmers.

Mass Balance Model

After the cotton leaves the gin, we use a mass balance chain of custody model. Mass balance is a volume-tracking system that allows Better Cotton to be substituted or mixed with conventional cotton by traders or spinners along the supply chain while ensuring that the amount of Better Cotton sold never exceeds the amount of Better Cotton purchased.

We use this model because supply chains are complex and mass balance helps to simplify the process while still delivering direct benefits to farmers, which is why it has been so effective at driving demand for sustainable practices worldwide.

How Does Mass Balance Work with Better Cotton?

Every 1kg of Better Cotton lint from the gin is assigned one Better Cotton Claim Unit (BCCU). As the cotton moves along the supply chain (beyond the gin) and is made into different products, these BCCUs are also passed along to represent the volume of Better Cotton sourced. BCCUs do not have to stay connected to the original Better Cotton sourced from Better Cotton Farmers. Want to know more about mass balance and Better Cotton? Take a look at our ‘What’s Behind the Logo?’ page.

The Better Cotton Platform

As Better Cotton is bought and sold along the supply chain, the associated BCCUs are recorded through the Better Cotton Platform (BCP). The BCP is an online system used only by the Better Cotton Initiative and registered supply chain organisations that buy, sell or source Better Cotton or cotton-containing products as Better Cotton. It enables suppliers and manufacturers to show customers how much Better Cotton lint was sourced through the sale of a physical product. By sourcing Better Cotton and cotton-containing products as Better Cotton, organisations create the demand for more sustainably grown cotton, creating further incentives for cotton farmers to adopt more sustainable farming practices and secure a better future for cotton. Learn more about the Better Cotton Platform.


There is a growing demand for traceable Better Cotton, as stakeholders worldwide seek more clarity over the social and environmental challenges associated with the cotton supply chain, and policymakers require businesses to demonstrate greater transparency. To achieve this, physical CoC models in addition to mass balance are needed to ensure Better Cotton farmers can continue to access increasingly regulated markets.

Documents and Guidance: Chain of Custody Guidelines v1.4

Chain of Custody Guidelines

The Better Cotton Chain of Custody Guidelines set out our requirements for organisations across the supply chain that are buying or selling Better Cotton or cotton-containing products as Better Cotton.

The guidelines are available in English and Mandarin below, along with a summary of changes and FAQs.

  • FAQs on the Chain of Custody Guidelines V1.4 148.23 KB

    This document is also available in the following languages:
  • Better Cotton Chain of Custody Guidelines: comparison of V1.3 with V1.4 588.06 KB

  • Chain of Custody Guidelines v1.4 421.64 KB

    This document is also available in the following languages:
Understanding Conversion Rates

Conversion Rates

When using a model of mass balance, conversion rates need to be taken into account. Conversion rates are the percentage of cotton fibres that are converted to useful cotton lint after the fibres have been separated from the seeds by the ginner. They allow us to calculate the volume of cotton lint required for an order of products that bear the Better Cotton logo.

In technical terms: the overall cotton consumption for a specific order of end products is the volume of total cotton lint consumed by the spinner who made the yarns that were used to make the fabrics that went into an end-product.

All BCCU allocations made during the sourcing of Better Cotton orders throughout the supply chain eventually support the sourcing of a Better Cotton end product order from a Better Cotton Retailer and Brand Member.

The Better Cotton Initiative uses two average conversion factors in the BCP to calculate the volume of cotton lint required for each product: one for combed yarn and another for carded or open-end yarn. In 2018 and 2019, we carried out research with our members that resulted in revised combed and carded conversion factors as well as a new one for open-end yarns. The publication that resulted from this research is available here.

On 4 January 2021, the revised conversion factors will come into effect on the BCP. The following table summarises the change that will take place.

Yarn TypeRevised Yarn to Lint conversion factors
(as of beginning of 2021)
Yarn to Lint Conversion Factors
(until end 2020)
Combed (ring-spun yarn)1.351.28
Carded (ring-spun yarn)1.161.1
Open-End (rotor yarn)1.111.1

This will lead to the following changes:

Yarn TypeBCCUs allocated with new conversion factors for 100 kgs of yarnBCCUs with old conversion factors for 100 kgs of yarn
Combed yarn135128
Carded yarn116110

It is important to note that the BCP only uses conversion factors for yarns, which are relevant for spinning activities. All other conversion factors given in our publication are used by other supply chain actors and Retailer and Brand Members to forecast the expected BCCUs they need for their Better Cotton orders.

The updated conversion factors will also change BCP routines used by suppliers and manufacturers. You can see the changes in this 7-minute video.

The Supplier Training Programme and the online training platform have also been updated to ensure that users understand the changes. Be sure to join an upcoming training session.

For any other questions relating to this change, see our FAQ page. You can also send your questions to [email protected] or reach out to your usual Better Cotton contact.

Supply Chain Monitoring and Audits

The Better Cotton Initiative carries out supply chain monitoring and audit activities to help ensure that companies sourcing Better Cotton comply with the relevant Chain of Custody requirements, as set out in the Better Cotton Chain of Custody Guidelines V1.4.

Reference documents and reporting templates are available below.

  • Overview of Better Cotton Supply Chain Monitoring 166.63 KB

  • Better Cotton Ginner Monitoring Reporting Template 265.66 KB

  • Better Cotton Supply Chain Audit Reporting Template 279.80 KB

Learn more

Find relevant Assurance Programme documents using the resources section.

Have any questions about the Better Cotton CoC? Send us a message.