# Transmission of price sheet NB to LF — LF view ## Process flow from the perspective of the LF \nSystem diagram: Übermittlung Preisblatt NB an LF — view of LF\n\n\nCustomer backend system\n\nMACO APP · LF\n\nMarket partner\n\n\n\n1. Preisblatt\n\nNB\n\nAS4\n27003\n\nAPERAK check: Z33\n\n\nCreate transaction\n\n\nCreate process data\n\nAPI\nkategorie = A\n\nUpdate transaction\n\n\nUpdate process data\n\nAPI\nkategorie = B\n"} gesamt={"\nSequence diagram: Übermittlung Preisblatt NB an LF — view of LF\n\n\nBackend (customer)\n\n\nMACO APP · LF\n\n\nNB\n\n\n1. Preisblatt\nAS4 · PI 27003\n\nCreate transaction\nCreate process data · kategorie = A\n\nUpdate transaction\nUpdate process data · kategorie = B\n"} titel="LF" /> ## Process steps ### Price sheet
**Check identifiers** - [27003](/en/schnittstellen/202604/pruefi/PRICAT/PI_27003) — Price sheets for NB services · AS4
**Flow**
  1. Message from **NB** · AS4
  2. **APERAK checks** - `27003` → `Z33` — APERAK check: Is referenced message known ?
  3. **Write endpoint** - `kategorie = A` → Transaction created — [Create process data](/en/api/202604/backend-schreiben-lf/createprocessdata#prozessdaten-erstellen) `POST /createProcessData` Try it out Creates a new transaction in the backend with the data of the incoming message.
  4. **Write endpoint** - `kategorie = B` → 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.
## Process information
  1. ### First message **NB** sends “Price sheet” (step 1). From here on, it is the turn of the party involved on this page.
## 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 NB](/en/prozessdoku/202604/NB/awh-sperrprozesse-gas-ubermittlung-preisblatt-nb-an-lf) — 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. :::