# Request for the supplier substitute energy clearing list, one-off or via a subscription — LF view The LF requests or, where required, subscribes to the LF-AACL from the NB. ## Process flow from the perspective of the LF \nSystem diagram: Anforderung der Lieferantenausfallarbeitsclearingliste einmalig oder durch ein Abonnement — view of LF\n\n\nCustomer backend system\n\nMACO APP · LF\n\nMarket partner\n\n\n\n1. Anforderung der\nLieferantenausfallarbeitsclea\nringliste einm…\n\nNB (ANB)\n\nAS4\n17210\n\nUpdate transaction\n\n\nUpdate process data\n\nAPI\n"} gesamt={"\nSequence diagram: Anforderung der Lieferantenausfallarbeitsclearingliste einmalig oder durch ein Abonnement — view of LF\n\n\nBackend (customer)\n\n\nMACO APP · LF\n\n\nNB (ANB)\n\n\n1. Anforderung der Lieferantenausfallarbeitsclea…\nAS4 · PI 17210\n\nUpdate transaction\nUpdate process data\n"} titel="LF" /> ## Process steps ### Request for the supplier substitute energy clearing list, one-off or by subscription
**Check identifiers** - [17210](/en/schnittstellen/202604/pruefi/ORDERS/PI_17210) — Request for supplier substitute energy clearing list · AS4
**Flow**
  1. Message to **NB (ANB)** · AS4
  2. **Write endpoint** - Transaction updated — [Update process data](/en/api/202604/backend-schreiben-lf/updateprocessdata#prozessdaten-aktualiseren) `POST /updateProcessData` Try it out Updates the existing transaction in the backend once the message has been created.
## Process information Wording of the consolidated version, profile ch. 17.3.2.5.1, p. 243.
  1. ### Preconditions For a single request: - The LF has the LF-AASZR from the NB. - The LF knows the MaBiS-ZP of the LF-AASZR. In the case of a subscription: the LF knows the MaBiS-ZP of the LF-AASZR.
  2. ### Further requirements If a subscription is requested again while a subscription already exists, from the point in time of receipt the recipient of the subscription refers to the new subscription in all LF-AACL resulting from it.
  3. ### First message The party involved on this page sends this itself: “Request for the supplier substitute energy clearing list, one-off or by subscription” to **NB (ANB)** (step 1).
  4. ### Objective The NB can start the process “Transmission of the LF-AASZR” (once or as a subscription).
## Other views of the process The same process through the eyes of the other parties involved: the same steps, each read from their point of view. - [View ANB](/en/prozessdoku/202604/NB/MaBiS-anforderung-der-lieferantenausfallarbeitsclearingliste-einmalig-oder-durch-ein-abonnement) — connecting grid operator · market role NB *The steps are the **possible** messages of this process, not a sequence — the source lists neither conditions nor alternatives. The small box on the step names the own view on the left: with **←** it receives, with **→** it sends. Collapsed steps run between other market partners.* The source does not yet name the event that triggers these steps. Applies to: [1](#schritt-1) For the check identifiers of these steps there is no test case in the test data set; the »Try it out« button of the write interface therefore offers no body. Applies to: [1](#schritt-1)