Yes, you can refer more than one dispute to Adjudication but the disputes must form part of one overall dispute. For example, a referring party can refer a dispute over payment to Adjudication.
In this dispute over payment of say £500,000, the referring party can list out the payments not made on one project.
For example the £500,000 might be made up of £200,000 on the first missed payment and £300,000 on the second missed payment.
The referring party can bundle these two missed payments as one dispute because they are part of the same overall dispute i.e. lack of payment.
In Quadro Services Ltd v Creagh Concrete Products 2021 this is exactly what happened. In this case Quadro referred a payment dispute over three separate invoices to adjudication.
Creagh defended by stating that the Adjudication cannot be for more than one issue. But the Adjudication ruled that the three issues were part of the same issue of non payment so the Adjudication went ahead and Quadro won.
It is established or settled law that an adjudicator has no jurisdiction if several disputes under the one contract are referred to adjudication. This means that if there are several disputes in a construction they must each be separately referred to adjudication unless they fall under the same umbrella of dispute.
For example, several issues over payment can be referred to one adjudication. But a dispute over a late payment plus a dispute over an extension of time cannot be referred to Adjudication together. They issues must be referred to separate adjudications. The reason for this approach is simple — Adjudication is supposed to a be fast and cheap method of dispute resolution and if you start complicating the issue in question then there is no way an Adjudicator can issue a decision within 28 days or keep the costs down.