FAR Subpart 2.1
Claim - "Claim" means a written demand or written assertion by one of the contracting parties seeking, as a matter of right, the payment of money in a sum certain, the adjustment or interpretation of contract terms, or other relief arising under or relating to the contract. However, a written demand or written assertion by the contractor seeking the payment of money exceeding $100,000 is not a claim under the Contract Disputes Act of 1978 until certified as required by the Act. A voucher, invoice, or other routine request for payment that is not in dispute when submitted is not a claim. The submission may be converted to a claim, by written notice to the contracting officer as provided in 33.206(a), if it is disputed either as to liability or amount or is not acted upon in a reasonable time.