> ## Documentation Index
> Fetch the complete documentation index at: https://docs.nomos.energy/llms.txt
> Use this file to discover all available pages before exploring further.

# Feed-in

> Sign up customers who feed solar power into the grid, with Nomos handling grid registration, metering, and monthly credits.

A feed-in subscription is the mirror image of a consumption subscription: energy flows from the customer's PV system into the grid, and money flows to the customer. You create it with the same [Create a subscription](/api-reference/subscriptions/create-a-subscription) call you already use for consumption signups; the plan's direction decides which rules apply. After reading this page you can identify feed-in plans, submit a valid feed-in signup, and know what Nomos does after the call returns.

<Note>
  Feed-in plans are available from the `2026-05-27.curie` API version onwards.
  On earlier versions they are hidden from the plans endpoints, and requesting a
  quote for a feed-in plan returns `400 BAD_REQUEST`. Pin your Auth Client or
  request to this version or later to work with feed-in.
</Note>

## How feed-in differs from consumption

* **Money flows the other way.** The customer is credited per kWh fed in, based on EPEX day-ahead spot prices. Credits surface through [List invoices](/api-reference/invoices/list-invoices) like any other billing document.
* **There is no supplier switch.** A feed-in signup registers the customer's generation with the grid operator; there is no previous contract to cancel.
* **Delivery starts on the first of a month.** Grid operators register feed-in to the start of a month and need about one month of lead time.
* **A smart meter must already be installed.** Feed-in quantities are metered per quarter-hour; without a smart meter (iMSys) there is nothing to credit.

## How it works

<Steps>
  <Step title="Find a feed-in plan">
    [List plans](/api-reference/plans/list-plans) and pick one with
    `type: "feed_in"`. Consumption plans carry `type: "consumption"`.
    Feed-in plans are configured per organization; ask Nomos support if none
    appear for yours.
  </Step>

  <Step title="Create the subscription">
    POST to [Create a
    subscription](/api-reference/subscriptions/create-a-subscription) with the
    feed-in plan. The shape is the same as a consumption signup, with the rules
    listed below.

    ```bash cURL theme={null}
    curl -X POST https://api.nomos.energy/subscriptions \
      -H "Authorization: Bearer ${ACCESS_TOKEN}" \
      -H "Content-Type: application/json" \
      -d '{
        "plan": "pln_bn1sny3aczwq5jkz8xcf4klf",
        "customer": {
          "type": "company",
          "company_name": "Sonnendach GmbH",
          "first_name": "Erika",
          "last_name": "Musterfrau",
          "email": "erika@sonnendach.example",
          "vat_id": "DE123456789"
        },
        "address": {
          "street": "Torstraße",
          "house_number": "119",
          "zip": "10115",
          "city": "Berlin"
        },
        "meter": {
          "number": "1APA0195124010",
          "type": "smart",
          "estimated_usage": 8500
        },
        "payment_method": {
          "type": "sepa_debit",
          "sepa_debit": {
            "iban": "DE68500105178297336485",
            "account_holder": "Sonnendach GmbH"
          }
        },
        "intended_start_date": "2026-08-01",
        "next_possible_start": false
      }'
    ```

    The response is the same subscription object as for a consumption signup;
    store its `id` for invoices, prices, and status changes, exactly as you
    would for consumption.

    For feed-in, `estimated_usage` is the expected annual feed-in quantity in
    kWh, not consumption.

    <Tip>
      Omit `intended_start_date` and set `next_possible_start` to `true` to
      start on the earliest possible date. Nomos picks the first of the next
      month that satisfies the lead time.
    </Tip>
  </Step>

  <Step title="Nomos registers the feed-in">
    Nomos identifies the customer's market location (MaLo) with the grid
    operator and registers the generation to the start date. No action is
    needed from you. The subscription behaves like a consumption subscription
    from here: [Retrieve a
    subscription](/api-reference/subscriptions/retrieve-a-subscription) returns
    `status: "pending"` until the start date is reached, then `"active"`.
  </Step>
</Steps>

## Signup rules

Requests that break a rule are rejected with `400 BAD_REQUEST` and a message naming the violated rule.

| Field                                                               | Rule for feed-in plans                                                                                                                         |
| ------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------- |
| `meter.type`                                                        | Must be `smart`. A smart meter has to be installed before the signup.                                                                          |
| `customer.vat_id`                                                   | Required when `customer.type` is `company`, optional for <br /> `customer.type: "person"` (see [How feed-in is taxed](#how-feed-in-is-taxed)). |
| <code style={{ whiteSpace: "nowrap" }}>intended\_start\_date</code> | Must be the first day of a month, at least one month out.                                                                                      |
| `previous_supplier`                                                 | Not supported. There is no contract to cancel.                                                                                                 |
| `product_orders`                                                    | Not supported. Smart meter ordering and §14a EnWG only apply to consumption.                                                                   |

## How feed-in is taxed

Feed-in remuneration is taxable revenue, and the rules depend on who operates the system. This is the background for the API's `vat_id` rule.

* **Private operators usually charge no VAT.** Most fall under the small business scheme of [§ 19 UStG](https://www.gesetze-im-internet.de/ustg_1980/__19.html) (up to 25,000 EUR previous-year revenue), so their credits are paid out without VAT. If a private customer does not fall under the scheme, pass their `vat_id` at signup and their credits break out VAT on top of the remuneration.
* **Companies receive credits that must satisfy invoice rules.** Nomos pays feed-in as a self-billing credit (Gutschrift), and [§ 14 UStG](https://www.gesetze-im-internet.de/ustg_1980/__14.html) requires such a document to carry the supplier's tax identification.

To preview the payout a customer will actually be credited, set `is_tax_exempt` on [Retrieve a quote](/api-reference/plans/retrieve-a-quote): an exempt customer is quoted the net payout, everyone else sees VAT included. Set it to match how the customer signs up (a person you submit without a `vat_id` is exempt, a company or a person with a `vat_id` is not) to keep the preview and the invoices in agreement.

<Note>
  This section summarizes the rules so the API behavior makes sense; it is not
  tax advice. Whether a specific operator is exempt depends on their overall
  situation, which their tax advisor can assess.
</Note>

## FAQ

<AccordionGroup>
  <Accordion title="Can a private person sign up without a VAT ID?">
    Yes. Without a VAT ID, a person's credits are treated as small-business
    payouts and show no VAT; with a VAT ID, the credits break out VAT (see [How
    feed-in is taxed](#how-feed-in-is-taxed)). Companies are assumed to be
    VAT-registered regardless, which is why `vat_id` is required for them.
  </Accordion>

  <Accordion title="How is the credited price determined?">
    Feed-in is credited based on EPEX day-ahead spot prices for the
    quarter-hours in which the customer fed in. Use [Retrieve a price time
    series](/api-reference/prices/retrieve-a-price-time-series) to show
    customers the prices their feed-in earns.
  </Accordion>

  <Accordion title="Can the customer order a smart meter as part of the signup?">
    No. A feed-in signup requires the smart meter to be in place already, so
    `product_orders` of type `smart-meter` are rejected. If the customer doesn't
    have one yet, the metering point operator (or a consumption signup with a
    smart meter order) has to get them there first.
  </Accordion>

  <Accordion title="Can one customer have both a consumption and a feed-in subscription?">
    Yes, and this is the common case for PV households: one consumption
    subscription for what they draw from the grid and one feed-in subscription
    for what they export. The two are separate subscriptions, typically on the
    same address with different meters or meter registers.
  </Accordion>
</AccordionGroup>