Advantages for Merchants

Taler is a cost-effective electronic payment system which provides you with cryptographic proof that the payment worked correctly within milliseconds. Your Web customers pay with previously unknown levels of convenience without risk of fraud.


Processing transactions with Taler is fast, allowing you to confirm the transaction with your customer virtually immediately. Your customers will appreciate that they do not have to type in credit card information and play the "verified by" game. By making payments significantly more convenient for your customers, you may be able to use Taler for small transactions that would not work with credit card payments due to the mental overhead for customers.


You will have cryptographic proof of payment from the Taler payment service provider. With Taler you never handle sensitive customer account information and thus do not have to undergo any particular security audits (such as PCI DSS). Your systems will have customer contracts with qualified signatures for all transactions which you can use in court in case of disputes.


Taler is free software, and you can use the liberally-licensed reference code as a starting point to integrate Taler into your services. To use Taler, you do not need to pay license fees, and the free software development model will ensure that you can select from many competing integrators for support.


Taler is uses efficient cryptographic constructions with low bandwidth and storage requirements. Combined with Taler's strong security which makes fraud impossible, Taler payment service providers can operate with very low overhead and thus offer low transaction fees.


Taler can be used for different currencies (such as Euros, US Dollars or Bitcoins) and any amount, limited only by applicable regulation and what denominations the payment service provider supports.


Taler prevents tax evasion and money laundering. Taler's protocols are efficient and do not use wasteful proof-of-work calculations. Taler encourages transparency by providing an open standard and free software reference implementations.

Manuals for merchants

  • The GNU Taler merchant backend operator manual (html, pdf)
  • The GNU Taler Web shop integration tutorial (PHP) (html, pdf)
  • The GNU Taler Web shop integration tutorial (Python) (html, pdf)

The GNU Taler Merchant Backend

Merchants process payments using the Taler backend:

  • The backend signs and stores the complete terms of offers made by the merchant to customers. For this, the merchant's frontend needs to give the customer's order in a JSON format to the backend.
  • The backend validates payments received from the wallet and executes them with the Taler payment service provider (the exchange). For this, the merchant's frontend must pass the payment request through to the Taler backend and check the HTTP status code that is returned.
  • The backend can list completed transactions and map wire transfers to sets of business transactions, including the exact terms of each contract.

customer perspective