• With Jack
• Have payment terms that incentivise clients to keep the project moving, such as billing to specific dates
• Add a 'pause clause' to your contract
• If your client is unhappy with the progress and their refusal to pay is accompanied with a threat, contact your insurer. Your professional indemnity insurance might be able to help
• If your client is claiming loss of income due to missing a deadline or asking for compensation to hire other freelancers, contact your insurer. Your professional indemnity insurance might be able to help