Who Owns a Customer-Specific Fine-Tuned Model and Its Training Data?

Oren CohenSources reviewed September 23, 202611 min read

The customer should. The adapter and the dataset derived from their production runs belong to the customer, serve that tenant only, and exist because the customer signed a written election. Most vendor terms, including Converra's, forbid training on customer data by default, so ownership starts with that exception.

Part 35 of the closed-to-open model transfer series. Ownership sounds like a legal footnote until the first customer asks to export their adapter, the first contract ends, or the first base model turns out to carry naming obligations. This part lists what an ownership position has to cover, in the order the questions usually arrive.

The short version

Ownership is not one sentence in a contract. It is the union of a written training election, tenant isolation, export rights for both weights and data, deletion and invalidation on termination, provider retention terms, and the base-model license obligations that travel with the artifact.

Start from the default: no training on customer data

Most AI service agreements promise that the vendor will not use customer data to train or improve any model. Converra's standard terms say exactly that, and define customer data broadly enough to include traces, prompts, transcripts, simulation outputs, and evaluation results. That promise is what customers rely on when they connect production traffic. A fine-tuning offer that touches customer data is an exception to it, and the exception has to be explicit.

The right shape is a written election: the customer opts in, in a signed order or amendment, to a fine-tuning engagement for named agents, with the model artifact and dataset scoped to that customer alone. Silence is not consent, a product setting is not consent, and a general clause permitting service improvement is not consent. Absent the election, the default holds and no training happens.

Tenant-exclusive means never reused, not just not shared

An adapter trained on one customer's conversations encodes that customer's rules, vocabulary, and sometimes their users' phrasing. It must never serve another tenant, and the examples must never enter another tenant's dataset, a shared base, or a vendor-owned model. This is a property to enforce mechanically, not a policy to remember: artifacts carry a tenant identifier, the serving layer refuses a mismatch, and the dataset build refuses cross-tenant lineage.

The vendor keeps what is genuinely its own: the pipeline, the review workflow, the gate contract, the evaluation methods, and any synthetic data it generated without customer inputs. The line is the source of the bytes. Anything derived from a customer's runs stays on the customer's side of it.

Ownership has to name the artifacts

Saying the customer owns the model is not enough, because a fine-tune produces several artifacts and they live in different places. There are the adapter weights, or the merged full weights if the adapter was folded in. There is the dataset version, with its examples and their lineage. There are the gate results, the training receipts, and the evaluation outputs. Each has an owner, a storage location, and an export path, or it has none and the ownership claim is hollow.

The practical test is portability. Can the customer take the adapter and run it on a different provider tomorrow? Can they take the dataset and retrain elsewhere? If a provider hosts the training and holds the weights, the contract with that provider has to grant export, and the customer needs to know that before they sign the election.

Question
Is training on this data permitted at all?
Default posture
No, under standard terms
What has to be written down
A signed election naming the agents, data, and scope
Question
Who owns the adapter or weights?
Default posture
The customer
What has to be written down
Export format, location, and the right to run it elsewhere
Question
Who owns the dataset?
Default posture
The customer
What has to be written down
Export of examples with lineage; no vendor reuse
Question
Can it serve another tenant?
Default posture
Never
What has to be written down
Mechanical tenant binding on artifacts and serving
Question
What happens at termination?
Default posture
Export then delete
What has to be written down
Deletion timeline, confirmation, and provider deletion
Question
What happens if data rights lapse?
Default posture
Artifact invalidated
What has to be written down
Which examples, which artifacts, and who decides
Question
What does the training provider retain?
Default posture
Depends on the provider
What has to be written down
Retention, residency, and subprocessor terms, re-read per engagement
Question
What does the base license require?
Default posture
Depends on the base
What has to be written down
Naming and attribution obligations that travel with the artifact

Deletion on termination has to reach every copy

When the engagement ends, the customer gets their export and the vendor deletes what it holds. The hard part is the third party. If training ran on a hosted provider, the dataset was uploaded there and the adapter was created there. Deletion has to be requested on that provider too, confirmed, and recorded. A vendor that deletes its own copy and leaves the provider's copy in place has not deleted anything from the customer's point of view.

Set the timeline before the engagement starts, and make deletion a receipt rather than a promise: a dated record of which artifacts were removed from which systems. The same applies to temporary evaluation endpoints, which hold the weights while they run and should be verified gone after each use, not assumed gone.

Rights can lapse, and the artifact has to know

Training data comes from production runs, and production runs involve end users whose data the customer holds under its own agreements. If a user withdraws consent, a data subject request lands, or a downstream customer of the customer leaves, some examples may lose their basis. A dataset with per-example lineage can find and remove them. A model trained on them cannot unlearn them.

Decide in advance what a rights lapse does to the artifact. The defensible rule is that the affected examples are removed from the dataset, the dataset gets a new version, and the current model is marked as trained on data that is no longer fully licensed. Whether that invalidates the model for serving is a decision for the customer and their counsel, but it has to be a decision someone is positioned to make, which requires the lineage to exist. Part 12 covers how to keep it.

The training provider's terms are part of the ownership picture

Hosted fine-tuning providers have their own terms about what they retain, where it lives, which subprocessors touch it, and what you may upload. Those terms change, and they apply to the customer's data the moment it is uploaded. A zero-retention promise for inference does not automatically extend to training data, and some providers place restrictions on the content of training inputs that a distillation dataset may or may not meet.

Re-read the provider's current terms for each engagement and record the version you reviewed. If the customer's data cannot leave their own cloud account, the engagement needs a training path inside that account, which is a different product with different costs. Part 42 goes into how provider terms shape what can be distilled at all.

The base model's license travels with the adapter

A LoRA adapter is meaningless without its base, and the base has a license. Qwen3's dense models are released under Apache 2.0, which permits commercial use and redistribution with attribution and notice preservation, and imposes no naming rule on derivatives. The Llama 4 Community License permits use but requires that a model built from the materials carry Llama at the beginning of its name and display Built with Llama where the model is offered. Those obligations attach to the customer's artifact, not just to the vendor's pipeline.

Ownership language has to acknowledge this. The customer owns their adapter, and their adapter is subject to the base license. Pick the base with the license obligations in view, record the license version in the dataset and model manifest, and make sure the customer knows which obligations they inherited before the election is signed.

What the vendor legitimately keeps

A vendor that builds this well has real intellectual property, and none of it is the customer's weights. It is the review workflow, the admission rules, the gate contract, the sizing method, the production verification machinery, and the operational method that turns a customer's reviewed evidence into a candidate and a verdict. Synthetic data the vendor authored from its own fixtures is its own. Aggregate, non-identifying operational metrics about the pipeline may be, depending on the agreement.

What the vendor may not keep is anything that lets it reconstruct the customer's data or reuse the customer's behavior. If a lesson from one engagement improves the method, the method improves. The examples that taught it stay where they came from.

Where Converra fits

Converra's standard terms state that customer data is not used to train, fine-tune, or improve any model, including models used to serve other customers, and its trust page describes that boundary. A customer-specific fine-tuning engagement is therefore possible only under a written, tenant-exclusive election, and the resulting adapter and dataset belong to the customer. Converra's fine-tuning workflow keeps per-example lineage in versioned datasets and records training jobs and gate results against those versions; the training itself runs on the customer's chosen provider or infrastructure, not on Converra.

Exact export formats, provider-side deletion procedures, and the handling of a rights lapse are engagement terms to be written down with the election rather than product defaults to assume. No customer fine-tuned model has been produced yet, so every one of these is a position to agree in advance rather than a practice to point at.

Frequently asked questions

Who owns a fine-tuned model trained on a customer's data?

The customer owns a fine-tuned model trained on their data, along with the dataset derived from their runs, under a written election that permits the training. The artifact is tenant-exclusive and is never reused for another customer.

Can a vendor train on customer data without explicit consent?

A vendor cannot train on customer data without explicit consent when its terms forbid it, which most AI service agreements do by default. A signed election naming the agents, data, and scope is the mechanism that permits a customer-specific fine-tune.

What happens to a fine-tuned model when the contract ends?

When the contract ends, the customer exports the adapter and dataset and the vendor deletes every copy it holds, including copies on the training provider and any evaluation endpoints, with a dated deletion receipt. The timeline should be agreed before the engagement starts.

Does the open-weight base model's license affect who owns the fine-tune?

The base model's license does not change who owns the fine-tune, but its obligations travel with the adapter. Apache 2.0 bases such as Qwen3 dense models impose attribution only, while the Llama 4 Community License requires Llama in derived model names and a Built with Llama notice.

What should happen to a model if the training data's rights lapse?

If training data rights lapse, the affected examples should be removed from the dataset through per-example lineage, a new dataset version created, and the current model flagged as trained on data no longer fully licensed. Whether it keeps serving is a customer decision that the lineage makes possible.

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