Any ‘pay when paid’ clauses in your contracts made after 1 August 2022 will have no effect. If your client relies on this kind of clause to delay paying you, make sure they are aware of the Building and Construction Industry (Security of Payment) Act 2021.
You could also consider making an adjudication application to seek payment. A client who can’t pay you could be a sign of concerning cash flow issues – it could be worth acting quickly to protect your rights.