The labels are used loosely in the industry, so go by what the business actually does with your certificates and your money.
The usual meanings
An aggregator collects certificates from many small suppliers, pools them into bulk lots and sells to liable entities or the clearing house. In most arrangements it buys from you as principal: you transfer, they pay you, and the market risk is theirs.
A broker is an intermediary. It finds a buyer, often takes a commission or a spread, and may not take title to the certificates. Payment can depend on the end buyer settling.
A trader often does both. Some traders act as agents in the registry as well, which is a separate role covered in what an STC agent is.
Differences that touch your cash flow
| Question | Aggregator or principal buyer | Broker |
|---|---|---|
| Who pays you | The buyer of your certificates | Often the end buyer, via the broker |
| Who carries price risk | Usually them, once the rate is locked | Depends on the deal |
| Typical cost | Embedded in the rate | A fee or spread |
| Failed claim | Per contract | Per contract |
Questions to ask
- Do you take title to my certificates, and when?
- Is my rate locked on lodgement?
- Do any fees or deductions apply?
- If the end buyer is slow, am I still paid on time?
A practical test
Ask one question and listen to the answer: ‘If your buyer pays you late, when do I get paid?’ A principal buyer answers that you are paid on the agreed terms regardless. An intermediary may say you are paid when they are. Another useful question is ‘Whose name appears as the transferee in the registry?’ If it is the business you are dealing with, they are taking the certificates. If it is a third party you have not heard of, you are in a brokered arrangement, and your contract should cover that clearly.
What this means for installers
For most small and mid-sized crews, selling to a principal buyer with a published rate is the simplest structure. Compare how it works at how it works and read the switching guide if you are thinking about a change. For VEECs the same logic applies, covered in what a VEEC aggregator is.