Void an AP payment with GL reversal
Authorization: requires purchasing:write API-key scope AND the per-user
payments.refund_void permission (SoD parity sweep 2026-05-16; AICPA SoD
4-role split treats AP void as highest-trust action — manager DENIED by default).
System-actor calls denied.
Voids an AP payment, reversing the disbursement GL journal entry (today-dated reversal in
the current open period — closed periods are never mutated), voiding the linked check
(including reversal of the check-cleared entry when the check had cleared), restoring any
vendor-credit consumption to the cent, and re-opening EVERY bill the payment covered via
the canonical AP balance writer. A multi-bill check payment re-opens ALL of its bills; call
GET /ap/payments/:id/void-preview (internal UI endpoint) or inspect void_summary in the
response to enumerate the effect. The void is reflected in the vendor’s AP aging immediately.
reason is REQUIRED (audited; 422 void_reason_required when absent). Typed rejections:
409 payment_already_voided (double-void), 409 historical_row_immutable (migrated rows),
422 ach_payment_not_voidable (ACH in flight or settled — cancel at the bank / record a
vendor credit instead), 422 payment_reconciled_blocks_void (matched to a bank statement
line — unmatch in reconciliation first), 409 credit_restore_conflict / 422
credit_restore_unresolvable (vendor-credit restoration cannot complete safely).
Requires purchasing:write scope.
Authorizations
API key issued per entity via Settings > Developers > API Keys.
Each key carries scopes (e.g. orders:read, products:write).
Bearer token format: Authorization: Bearer ark_live_ent_Test keys use ark_test_ent_. Both are issued per entity
via Settings > Developers > API Keys.
Path Parameters
Body
Audited void reason. Stamped into the reversal journal entries, the activity log, and the check's void_reason.
Response
Voided AP payment. Includes void_summary (reversed_journal_entry_ids, reopened_bills, restored_credits, check).
A payment Arcus made to a vendor (AP-side).
ap_payment Set when payment is applied to a single bill; null for batch/on-account.
check, ach, wire, credit_card, cash, other Check number, ACH trace, etc.
pending, sent, cleared, voided, returned 
