Volksbank Hamm / Sieg API & Open Banking Access

Reaching account data from Volksbank Hamm / Sieg — the co-operative bank serving Hamm (Sieg) and the wider Westerwald in Rhineland-Palatinate — no longer requires a bank-issued API programme or an eIDAS certificate. open-banking.io links your Volksbank Hamm / Sieg accounts (BIC GENODE51HAM) under standard PSD2 access and hands the decrypted data back only to you. Both business and personal accounts are supported, and each consent stays valid for up to 180 days before Volksbank Hamm / Sieg asks you to renew it.

The difference is where the trust sits. Your encryption keys are generated on your own device, so open-banking.io stores only your public key and never sees readable balances or transactions.

How to connect Volksbank Hamm / Sieg

Connecting happens entirely inside the open-banking.io dashboard — there is no endpoint to call and no key to paste:

  1. Sign up for open-banking.io and set your encryption passphrase. Your private key is created locally and never leaves your device.
  2. In the dashboard, pick Volksbank Hamm / Sieg from the bank list and choose the account type — business or personal.
  3. You are redirected to Volksbank Hamm / Sieg's own secure login, where you approve the PSD2 access request on the bank's consent screen.
  4. Once approved, your accounts sync straight into your dashboard, ready to view.

That is the whole flow. No developer setup, no OAuth glue, no redirect you have to build yourself.

Access your data

Programmatic access is an optional step you take after the connection exists. On the Developers page, create an API key and export a credentials.json — this bundles the API key together with your private decryption key. From there you can use the CLI (openbanking accounts, openbanking transactions, openbanking sync), an SDK, or the REST API. Every request carries your key in the X-Api-Key header, and each response is decrypted locally with your own key. An API key by itself only ever returns ciphertext — the readable data appears only on your machine. The CLI and SDK read and sync existing connections; they never create them.

Pricing is a flat ~EUR 3/month, with no per-call fees and no certificate to purchase or renew.

Does open-banking.io see my Volksbank Hamm / Sieg data?

No. It is zero-knowledge and holds only your public key. Decryption happens on your device with a key only you control.

Which Volksbank Hamm / Sieg accounts work?

Both business and personal accounts under BIC GENODE51HAM are supported.

How long does access last?

Consent runs up to 180 days, after which you re-approve on Volksbank Hamm / Sieg's own login screen.

Start at open-banking.io.