A battery passport is not only a web page with a QR code. It is a regulated artefact that must implement the Annex XIII access tiers, carry ISO/IEC 15459 unique identifiers, remain reachable for a long retention period, and reflect the per-battery granularity required by Article 77(1). The build-versus-buy decision is therefore about who absorbs the regulatory interpretation and the long-term operational burden.
| Dimension | Build in-house | Dedicated tool |
|---|---|---|
| Regulatory mapping | You interpret Annex XIII and Art. 77(1) yourself | Field set and access tiers are pre-mapped |
| Time to first passport | Weeks to months | Set by your data, self-serve |
| Access-tier enforcement | You build server-side gating | Enforced by the platform |
| 10-year retention | You own hosting and durability | Provided as a service |
| Ongoing maintenance | Your engineers, indefinitely | Handled by the vendor |
| Cost shape | Engineering time + infrastructure | Published plans, extra passports priced openly |
When building can make sense
- You have very high volumes and existing in-house compliance and platform engineering capacity.
- You need deep, custom integration with proprietary systems that a generic tool will not cover.
- You are prepared to own regulatory interpretation and long-term hosting durability.
When buying usually wins
- You need a compliant passport before 18 February 2027 without a multi-month project.
- You do not want to build and maintain server-side Annex XIII tier enforcement yourself.
- You prefer predictable, published pricing over open-ended engineering cost.
Frequently asked
Is it cheaper to build a battery passport system in-house?
It can look cheaper for the first version, but the 10-year retention obligation, access-tier enforcement and ongoing regulatory updates usually make total cost of ownership higher than a tool on a published plan unless you operate at very large scale.
What is the main risk of building in-house?
Misinterpreting the regulation — for example implementing per-model passports instead of the per-battery passports required by Article 77(1), or failing to enforce the Annex XIII access tiers server-side.