text: **II.21.6. Interim payments and payment of the balance**
  
  The contractor (or leader in the case of a joint tender) must send an invoice for interim 
  payment, as provided for in Article I.6 or in the tender specifications or in the specific 
  contract. 
  
  The contractor (or leader in the case of a joint tender) must send an invoice for payment 
  of the balance within 60 days of the end of the period of provision of the services, as 
  provided for in Article I.6, in the tender specifications or in the specific contract. 
  
  Payment of the invoice and approval of documents does not imply recognition of the 
  regularity, authenticity, completeness and correctness of the declarations and information 
  they contain. 
  
  Payment of the balance may take the form of recovery. 
  
  **II.21.7. Suspension of the time allowed for payment**
  
  The contracting authority may suspend the payment periods specified in Article I.6 at any 
  time by*notifying*the contractor (or leader in the case of a joint tender) that its invoice 
  cannot be processed. The reasons the contracting authority may cite for not being able to 
  process an invoice are: 
  
  (a) because it does not comply with the FWC; 
  (b) because the contractor has not produced the appropriate documents or 
  
  deliverables; or 
  
  (c) because the contracting authority has observations on the documents or 
  deliverables submitted with the invoice. 