Build the year's Forms 1099-INT as a Publication 1220 file and retain it as a proposed IRS FIRE transmission awaiting a second reviewer (Idempotency-Key); body {year, blank_missing_tin}
POST
/tax-forms/1099-int/transmissionsHeaders
Idempotency-KeystringOptionalSend on every write that creates or changes money or state; a replay with the same key returns the original result with 200.
Returns
200 OK
Errors
Every error is a problem document with a stable code. See Errors.
400401403404409412413422424429500503