Bank Millennium Open Banking & API Access (Poland)

Bank Millennium is one of Poland's largest retail and business banks, and open-banking.io lets you reach its account and transaction data without wrestling with PSD2 certificates, sandbox registrations or bespoke bank APIs. You connect once in your browser, and your Bank Millennium data flows into a dashboard where it is decrypted locally with a key that never leaves your device. open-banking.io covers 2,600+ EU and UK banks, so Bank Millennium sits alongside every other account you hold.

Both business and personal Bank Millennium accounts are supported, and a single approval keeps your access live for up to 180 days before you need to renew consent. Bank Millennium does not publish a BIC in our directory (BIC not available), which is fine — open-banking.io identifies the bank for you during connection.

How to connect Bank Millennium

Connecting happens entirely inside the open-banking.io dashboard — there is no API call, code or key involved in this step.

1. Sign up for open-banking.io and set your encryption passphrase. Your cryptographic keys are generated right there on your own device.
2. Open the dashboard, search for Bank Millennium, and choose whether you are linking a business or personal account.
3. You are redirected to Bank Millennium's own secure login, where you approve the PSD2 access request directly with the bank.
4. Once you confirm, your accounts sync back into the dashboard and stay up to date for the duration of your consent.

Because approval takes place on Bank Millennium's own screens, open-banking.io never sees your banking credentials.

Access your data

After your Bank Millennium accounts are connected, developers can optionally read the data programmatically. On the Developers page, create an API key and export a credentials.json — this bundles the API key with your private decryption key. From there you can use the CLI (openbanking accounts, openbanking transactions, openbanking sync), an SDK, or the REST API. Requests carry your key in the X-Api-Key header, and every response is decrypted locally with your private key. An API key alone only ever returns ciphertext.

This is the zero-knowledge, certificate-free model: open-banking.io holds only your public key, so it can never read or decrypt your Bank Millennium data. All of it runs for roughly EUR 3/month.

Do I need a PSD2 certificate for Bank Millennium?

No. open-banking.io handles the regulated connection, so you never obtain or manage certificates yourself.

Can I connect both business and personal accounts?

Yes. Bank Millennium supports both account types, and you can link each one separately in the dashboard.

How long does access last before renewal?

Each Bank Millennium consent stays valid for up to 180 days, after which you simply re-approve in the dashboard.

Ready to start? Visit open-banking.io to connect Bank Millennium today.