The TRN02 (and the front matter) in the 835 states:
If payment is made by check, this must be the check number
If payment is made by EFT, this must be the EFT reference number
This implies that the 835 cannot be sent until the check number/EFT number is known, but I have not seen that stated anywhere. Is it compliant to send other values in this data element?
For example: the RA number if the warrant amount is 0 and the Warrant Number if the warrant amount is greater than 0? The check/EFT number is not known for several days after the payment cycle and would delay the 835.
This is explicitly addressed in the 835 1.10.2.2 Remittance Tracking stating that the payment number must be made available via the payment process. Either a check number or EFT number must be reported when Total Actual Provider Payment Amount (BPR02)is greater than zero. If there is no payment, a unique remit number must be supplied. According to the TR3 the Warrant number is not an acceptable number to use in the TRN02 field.
This note can be found on the element detail for TRN02: “This number must be unique within the sender/receiver relationship. The number is assigned by the sender. If payment is made by check, this must be the check number. If payment is made by EFT, this must be the EFT reference number. If this is a nonpayment 835, this must be a unique remittance advice identification number.”