A market boundary is the geographic area, usually a single electricity grid or country-level jurisdiction, where power gets generated and used. The GHG Protocol Scope 2 Guidance (soon to undergo revision to tighten this rule further in Europe) and RE100 both require that market-based renewable energy claims stay inside these boundaries, including regulatory boundaries (regulatory regimes must be shared within a market boundary to enable a valid transfer). So a REGO bought in the UK can only back UK consumption, a Guarantee of Origin covers AIB-Hub connected countries (or, increasingly, operates via "AIB grid-connected" principles), a REC works in North America, and an I-REC applies in the country where it was issued. The certificate has to match where your actual electricity load sits. When a company operates across multiple countries, each with its own registry and rules, keeping track of all this becomes a real headache, leading teams to turn to platforms with global registry integrations and virtual accounts like Soldera.