# Start of supply — LFN view ## Process flow from the perspective of the LF (LFN) \nSystem diagram: Lieferbeginn — view of LF\n\n\nCustomer backend system\n\nMACO APP · LF (entspricht…\n\nMarket partner\n\n\n\nProcess trigger received\n\nSTART_LIEFERBEGINN\n\nAPI\n\n1. Anmeldung\n\n\nNB\n\nAS4\n44001\n\nUpdate transaction\n\n\nUpdate process data\n\nAPI\n\n2. Information über\nexistierende Zuordnung\n\n\nNB\n\nAS4\n44036\n\nAPERAK check: Z33\n\n\nUpdate transaction\n\n\nUpdate process data\n\nAPI\n\n5. Antwort auf Anmeldung\n\n\nNB\n\nAS4\n44003, 44002\n\nAPERAK check: Z33\n\n\nUpdate transaction\n\n\nUpdate process data\n\nAPI\n"} gesamt={"\nSequence diagram: Lieferbeginn — view of LF\n\n\nBackend (customer)\n\n\nMACO APP · LF (entspricht…\n\n\nNB\n\n\nLF (entspricht LFA)\n\n\nLF (zukünfitge LF)\n\n\nSTART_LIEFERBEGINN\nTrigger event\n\n1. Anmeldung\nAS4 · PI 44001\n\nUpdate transaction\nUpdate process data\n\n2. Information über existierende Zuordnung\nAS4 · PI 44036\n\nUpdate transaction\nUpdate process data\n\n3. Abmeldeanfrage\nAS4 · PI 44010\n\n4. Beantwortung der Abmeldeanfrage\nAS4 · PI 44011, 44012 · E_3020\nE_3020 — Abmeldung prüfen\n\n5. Antwort auf Anmeldung\nAS4 · PI 44003, 44002 · E_3005, E_3007\nE_3005 — Prüfen, ob Anmeldung direkt ablehnbar\nE_3007 — Lieferbeginn prüfen\n\nUpdate transaction\nUpdate process data\n\n6. Mitteilung über Beendigung der Zuordnung\nAS4 · PI 44037\n\n7. Information über die Aufhebung einer zukünfti…\nAS4 · PI 44038\n"} titel="LFN" /> ## Process steps ### Registration
**Check identifiers** - [44001](/en/schnittstellen/202604/pruefi/UTILMD_GAS/PI_44001) — NN registration · AS4
**Flow**
  1. **Prozessauslöser** [`START_LIEFERBEGINN`](/en/api/202604/ausloeser-lf/start-lieferbeginn) \"\n ]\n }\n ],\n \"ENERGIELIEFERVERTRAG\": [\n {\n \"korrespondenzpartner\": {\n \"name1\": \"\"\n },\n \"vertragskonditionen\": {\n \"abrechnungsintervall\": \"\"\n },\n \"vertragspartner2\": [\n \"\"\n ]\n }\n ],\n \"MESSLOKATION\": [\n {\n \"ablesekartenempfaenger\": {\n \"name1\": \"\"\n }\n }\n ],\n \"NETZNUTZUNGSVERTRAG\": [\n {\n \"gemeinderabatt\": null,\n \"vertragskonditionen\": {\n \"haushaltskunde\": \"\",\n \"netznutzungsvertrag\": \"\",\n \"netznutzungszahler\": \"\"\n }\n }\n ]\n },\n \"transaktionsdaten\": {\n \"absender\": {\n \"rollencodenummer\": \"\"\n },\n \"empfaenger\": {\n \"marktrolle\": \"\",\n \"rollencodenummer\": \"\"\n },\n \"kategorie\": \"\",\n \"sparte\": \"\",\n \"transaktionsgrund\": \"\",\n \"transaktionsgrundergaenzung\": \"\",\n \"vertragsbeginn\": \"\"\n },\n \"zusatzdaten\": {\n \"eventname\": \"START_LIEFERBEGINN\",\n \"prozessId\": \"\"\n }\n}"} security={[{"bearer": []}]}>Ausprobieren The backend triggers this step with this event.
  2. Message to **NB** · AS4
  3. **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.
### Information about existing assignment
**Check identifiers** - [44036](/en/schnittstellen/202604/pruefi/UTILMD_GAS/PI_44036) — Information notification about existing assignment · AS4
**Flow**
  1. Message from **NB** · AS4
  2. **APERAK checks** - `44036` → `Z33` — APERAK check: Is referenced message known ?
  3. **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 with the data of the incoming message.
### Deregistration request This step runs between other market partners and is not relevant for this view.
**Check identifiers** - [44010](/en/schnittstellen/202604/pruefi/UTILMD_GAS/PI_44010) — Deregistration request from the NB · AS4
### Response to the deregistration request This step runs between other market partners and is not relevant for this view.
**Check identifiers** - [44011](/en/schnittstellen/202604/pruefi/UTILMD_GAS/PI_44011) — Confirmation of deregistration request · AS4 - [44012](/en/schnittstellen/202604/pruefi/UTILMD_GAS/PI_44012) — Rejection of deregistration request · AS4
**Response per decision tree** - `44011`, `44012` → [E_3020](/en/referenz/202604/ebd/E_3020) · Check deregistration
### Response to registration
**Check identifiers** - [44003](/en/schnittstellen/202604/pruefi/UTILMD_GAS/PI_44003) — Rejection of registration · AS4 - [44002](/en/schnittstellen/202604/pruefi/UTILMD_GAS/PI_44002) — Confirmation of registration · AS4
**Flow**
  1. Message from **NB** · AS4
    **Response per decision tree** - `44003` → [E_3005](/en/referenz/202604/ebd/E_3005) · Check whether the registration can be rejected directly - `44003`, `44002` → [E_3007](/en/referenz/202604/ebd/E_3007) · Check start of supply
  2. **APERAK checks** - `44003`, `44002` → `Z33` — APERAK check: Is referenced message known ?
  3. **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 with the data of the incoming message.
### Notification of the termination of the assignment This step runs between other market partners and is not relevant for this view.
**Check identifiers** - [44037](/en/schnittstellen/202604/pruefi/UTILMD_GAS/PI_44037) — Information notification on termination of the assignment · AS4
### Information about the cancellation of a future assignment This step runs between other market partners and is not relevant for this view.
**Check identifiers** - [44038](/en/schnittstellen/202604/pruefi/UTILMD_GAS/PI_44038) — Information notification on revocation of a future assignment · AS4
Decision trees of this process | EBD | Name | |---|---| | [E_3005](/referenz/202604/ebd/E_3005) | Check whether the registration can be rejected directly | | [E_3007](/referenz/202604/ebd/E_3007) | Check start of supply | | [E_3020](/referenz/202604/ebd/E_3020) | Check deregistration |
## Process information
  1. ### Trigger **Runs beforehand:** [Billing data for grid usage settlement](/en/prozessdoku/202604/LF/GPKE-Teil2-abrechnungsdaten-netznutzungsabrechnung), [Determination of the MaLo ID of the market location](/en/prozessdoku/202604/LF/GPKE-Teil2-ermittlung-der-malo-id-der-marktlokation), [Creation](/en/prozessdoku/202604/LF/GPKE-Teil2-neuanlage) — these processes name the one shown here in their result.
  2. ### First message The party involved on this page is itself the sender of: „Registration“ to **NB** (step 1).
## 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 LFA](/en/prozessdoku/202604/LF--LFA/geli-gas-2-0-lieferbeginn) — the transferring supplier · market role LF - [View LFZ](/en/prozessdoku/202604/LF--LFZ/geli-gas-2-0-lieferbeginn) — future supplier · market role LF - [View NB](/en/prozessdoku/202604/NB/geli-gas-2-0-lieferbeginn) — NB *The source provides no use case profile for this process — objective, precondition and result are not recorded there.* *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.* :::caution{title="Step sequence reconstructed"} For this process, the BNetzA consolidated version carries no sequence diagram. The steps are reconstructed from the BDEW check identifier table: grouped by the designation, ordered by the process step. The method agrees with the consolidated version in 200 of 200 cases that can be cross-checked — the individual line is nevertheless not editorially reviewed. Check it against the rulebook before adopting it into an implementation specification. :::