The easiest way is to define what a MOCAS contract is:
MOCAS is a contract administered by a Defense Contract Management Agency (DCMA) and paid by DFAS Columbus, either North, South, or West Entitlements. Basically all other contracts paid by a DFAS location are Non-MOCAS and considered Vendor Pay. Look on the front page of your contract in the box titled 'Payment Will Be Made By'. There should be a six digit code here.

The preferred method of submitting invoices is electronically via Wide Area Workflow (WAWF). WAWF is an interactive web-based application that allows vendors/contractors to electronically submit invoices and receiving reports; and for the Government to inspect, accept, receive, and pay electronically. Go to: http://www.dfas.mil/dfas/ecommerce.html for more information. In accordance with Defense Federal Acquisition Regulation Supplement (DFARS) dated March 2008, requires the use of the WAWF electronic system for submitting and processing payment requests and receiving reports under Department of Defense (DoD) contracts. Use of WAWF facilitates timely and accurate payments of DoD contractors. For WAWF registration and more information, go to: http://www.dfas.mil/dfas/ecommerce.html  DFAS also uses Electronic Data Interchange (EDI). EDI is the computer to computer exchange of routine business information in a standard format.
Note: If you have already submitted the invoice electronically, do not fax it, as it will result in a duplicate and could cause payment delays.

2a. How do I invoice Electronically for DISA (HQ0252) Telecommunication’s Invoices?  
If you are currently printing and submitting paper Invoices that are paid in DITCO FABS for Telecommunications (HQ0252), there is a better way – It is safe, secure, and the process saves both time and money for both DFAS and the vendor.   What is it? DITCO Electronic Invoicing Process.   There are currently several ways to submit TELCOM invoices electronically:  
-By Secure File Transfer Protocol (FTP) through the DFAS Corp Server
-By Mainframe Transfer
-By Delivery Ticket Invoicing (DTI)
-By CD  
This electronic process saves both DFAS and the vendor processing time and money.    For more information on converting to the DITCO Electronic Invoicing Process, email  CCO-FABS@DFAS.MIL; subject line - Electronic.
 

It is a web-based application for vendors/contractors to track status on invoices submitted and processed into the payment entitlement system.  The contract must be paid by a DFAS location.  Government entities can request access to myInvoice for research purposes.  myInvoice consolidates invoice information for both paid and unpaid invoices, obtained from several DFAS payment systems into one central repository. 
For additional info, go to: https://myinvoice.csd.disa.mil

SAM is the primary vendor database for the U.S. Government. SAM collects, validates, stores, and disseminates data in support of agency acquisition missions. Both current and potential government vendors are required to register in SAM in order to be awarded contracts by the government. For additional information, go to http://www.sam.gov .  The Commercial and Government Entity (CAGE) Code is a five digit ID number used extensively within the DoD and NASA.  The Data Universal Numbering System (DUNS) is a unique nine digit number provided by the commercial company: Dun and Bradstreet (D&B).   For additional info on DUNS, call 866-705-5711.

• Contractor's/Vendor's Name and Address
• Invoice Date/Number
• Government Contract Number/Purchase Order Number
• Shipment Number
• Description of Goods/Services (CLIN, QTY, U/P), Quantity, Unit Price, Total Amount of Invoice
• Taxpayer Identification Number (TIN) (if applicable)
• If using a DD250 as an invoice, the wording ‘Original Invoice’ or ‘Invoice’ in 1-inch high letters must appear on the invoice. Do not use red or green ink.  Black ink works best in our imaging system. 
• Must be registered and current in System for Award Management (SAM), to verify your status, go to: https://www.sam.gov/
• Contact name of person to be notified in event of a defective invoice

Note: An invoice will not be considered proper if it is received manually and the contract requires electronic submission.

Progress payments are payments made based on the cost incurred by the contractor/vendor as work progresses under a contract.  When authorized in the contract, DFAS can make payments of 80% or more of the accumulated costs on certain items.

Performance based payments (PBP) is a alternative to progress payments for contract financing.  This financing is based on certain specified performance criterion being accomplished versus cost accumulation which is the basis for progress payments.  Federal Acquisition Regulation Clause 252.232-32 must be included in the contract for PBP.

A receiving report is not required before payment can be made for purchases under the “Fast Pay” procedures.  The receiving report can be forwarded after the payment is made.  For additional info, go to: http://farsite.hill.af.mil, and research FAR 52.213.1

Payment due dates are calculated in accordance with Federal Acquisition Regulation (FAR) 52.232-25.  The due date for making invoice payments by the designated payment office shall be the later of the following two events (excluding the exceptions noted in FAR 52.232-25:

• The 30th day after the designated billing office has received a proper invoice from the contractor.
• The 30th day after the Government acceptance of supplies delivered or services performed by the contractor. However, if the designated billing office fails to annotate the invoice with the actual date of receipt, the invoice payment due date shall be deemed to be the 30th day after the contractor’s invoice is dated, provided a proper invoice is received and there is no disagreement over quantity, quality, or contractor compliance with contract requirements, whichever is the later date. 

Note:  Progress payments are payable within 7 days.  Cost vouchers, performance based payments, and BVNs are payable within 14 days.  Commercial invoices and DD250s are payable within 30 days.

The Central Contractor Registration system (CCR) was replaced by the System for Award Management (SAM). SAM is combining federal procurement systems and Catalog of Federal Domestic Assistance into one new system.