What is on your documents, why, and which rules are behind it.
MeterGate provides the API service in its own name for the account of the provider (commissionaire, § 3(11) of the German VAT Act, UStG). MeterGate is therefore your contracting party and the issuer of your invoice, not the individual provider. You receive one invoice per provider and calendar month.
Every invoice carries the mandatory details under § 14 UStG: issuer with tax number or VAT ID, sequential invoice number, period of service, amount, tax rate and tax amount. For each product it states how many calls were billed and the price per call. Businesses in Germany reclaim the VAT shown on it.
The invoice is an e-invoice in the Factur-X format, profile EN 16931: the structured data set is embedded in the PDF file (factur-x.xml), document type 380. Any accounting software that reads e-invoices can book it directly. For transactions between German businesses this format becomes mandatory for everyone on 1 January 2028 (§ 27(38) UStG).
All prices in the catalog are net prices. For buyers based in Germany, statutory VAT is added. Businesses based in another EU member state receive the invoice without German VAT; the tax liability shifts to them (reverse charge, § 3a(2) UStG).
MeterGate settles your share by self-billing invoice (Gutschrift, § 14(2) sentence 5 UStG). You do not issue an invoice of your own for it. The self-billing invoice is also an e-invoice (document type 389) and is available under Products → Earnings. Providers from other EU member states receive it without VAT; MeterGate owes the tax. Your share is 85 percent before Stripe fees.
Invoices and self-billed invoices remain available in your account for as long as it exists. MeterGate retains them for the statutory period (§ 14b UStG, § 147 AO), also after the contract has ended.