Additional Terms — NumberingSeries

These Additional Terms supplement the Terms of Service for the NumberingSeries Service. Capitalised terms not defined here have the meaning given in the Terms.

In case of conflict between the Terms and these Additional Terms, these Additional Terms prevail to the extent of the conflict.

1. Service description

NumberingSeries is an API that generates sequential identifiers (e.g. invoice numbers, order numbers) according to a format pattern defined by the Customer. Each named series maintains a counter; calls to the API atomically increment the counter and return the next rendered value.

The Service exposes:

• a REST API for series management and number generation;
• a web panel for managing API keys and your Subscription.

2. Data we process

For each Customer of NumberingSeries we process:

• account data and authentication data (as described in the Privacy Policy);
• series configuration you create: the identifier you assign, the format pattern, the counter state, and other configuration you provide for the series to operate as you intend;
• rendered values returned to your callers: opaque text strings as defined by your format;
• idempotency keys: short-lived (24 h) values you supply to deduplicate retries of the same logical operation;
• audit events: lifecycle records of series creation, increments, and administrative actions.

NumberingSeries does not require you to submit personal data to function. Series friendly names and format patterns are intended to be free of personal data; if you choose to embed personal data in them, you do so as controller and you alone are responsible for the lawfulness of that processing.

3. Quotas, rate limits, and overage

• Quotas per plan are published on the Service's pricing page.
• Calls in excess of your quota are rejected with an error response and not charged. Quotas reset at the start of each billing period.
• Per-key short-burst rate limits may apply to protect the Service; current values are documented in the API Reference.

How calls are counted. Each call to a NumberingSeries API endpoint counts against your monthly quota if it was made with a recognised API Key, passed quota and rate-limit checks, and reached the Service's request handling. This applies uniformly to all API endpoints — series management operations (create, list, retrieve, update, delete) and number generation (/next) — each counts as a single call. The following table shows which outcomes count and which do not:

Outcome	Counts toward quota?
Successful response from any NumberingSeries API endpoint — a number was issued, or a series was created, listed, retrieved, updated, or deleted	Yes
The request was authenticated but the Service rejected it for a reason within your control — for example, an unrecognised series name, a malformed format pattern, or a missing required field	Yes — the request was authenticated and the Service performed work to process and reject it
Authentication failed — the API Key was missing, unrecognised, or the Subscription was not active	No — the caller is not identified as a Customer for billing purposes
Rejected because your monthly quota was already exhausted	No — you cannot be charged for the Service's own rejection
Rejected by the per-second rate limit	No — same reason
Failed because of a fault on our side	No
A retry to the /next endpoint that returns a previously issued value (within the idempotency window)	Yes — each call consumes Service resources regardless of whether a new value is issued

The intent of these rules is that you cannot circumvent the quota by submitting invalid requests, but you are not charged for rejections caused by our own limits or faults. This approach is consistent with how quota-metered APIs are typically defined across the industry.

The web panel does not consume your API quota. The web panel for managing your account, API Keys, and Subscription uses session-based authentication and does not count against the monthly call quota. Only requests authenticated with an API Key against the REST API are counted.

4. Service availability

The Service is provided on an as-is, as-available basis. No formal SLA is offered on Solo, Starter, or Pro plans. Enterprise SLAs are negotiated individually.

5. Idempotency and concurrency guarantees

• Calls that issue the next number in a series are idempotent within a 24-hour window when the same idempotency key is supplied. A retry returns the previously issued value unchanged.
• Concurrent calls to the same series are serialised: the same number is never issued twice, regardless of how many parallel calls are in flight.
• Idempotency keys older than 24 hours are automatically deleted. A retry beyond that window will produce a new number.

6. Customer responsibilities

You are responsible for:

• defining series formats appropriate to your business and regulatory requirements (we make no representation that any particular format meets the requirements of any tax or accounting authority);
• verifying the correctness of every value returned by the API before relying on it.
  • Business Customers (as defined in §3a of the Terms of Service): you must validate that each returned value matches your expected format, sequence, and business rules before issuing it to an end customer, embedding it in an invoice or other legal document, or persisting it as the authoritative identifier in your systems. We are not liable for consequences arising from reliance on an API response that you did not verify.
  • Consumer Customers: you are strongly advised to validate each returned value before relying on it for any purpose where an error would be costly or hard to reverse. Your statutory rights as a consumer are not affected by this advisory.
• safeguarding API Keys and rotating them on personnel changes;
• backing up the rendered values you receive from the API; we retain audit history but you should treat the API call as the moment of issuance for your records.

6a. Liability — service-credit cap for Business Customers

For a Business Customer, the cap on aggregate liability under §13 of the Terms of Service is further refined as follows for this Service:

• Our total aggregate liability for any claim arising out of or related to NumberingSeries is limited to a service credit equal to the fees paid for the calendar month in which the event giving rise to the claim occurred, applied against the next invoice after the claim is resolved.
• A Business Customer's sole and exclusive remedy under this Service is the service credit described above. No cash refund is payable in lieu of service credit except where required by mandatory law.

For a Consumer Customer, the standard cap in §13 of the Terms of Service applies (lower of 12 months of fees or €100), without limitation of any mandatory consumer right.

7. Data retention specific to NumberingSeries

Data	Retention
Series and counter state	For the lifetime of your account; deleted immediately on account closure (no recovery window)
Audit events for a series (creation, updates, deletion, each number issued, and automatic idempotency-key cleanup)	For the lifetime of your account; deleted on account closure
Idempotency keys	24 hours, then automatically deleted

8. No re-issuance after deletion

Series deletion is permanent. We will not re-create a deleted series with the same friendly name and prior counter value, and we will not roll a counter back to a prior value, except where required by law or to remediate a confirmed Service defect on our side.

9. Changes to the Service

We may add, change, or remove features. Material changes that affect interoperability with your integration are notified at least 30 days in advance.