The default secret answer for all sandbox accounts is "Simon". This is used for password resets and obtaining new transaction key.
The API Login ID and Transaction Key are two pieces of information unique to your account. They are only used to connect your website or other integrated business application to the Authorize.Net® Payment Gateway for transaction processing. They are not valid for logging into the Merchant Interface. The API Login ID is at least eight characters in length and Transaction key contains 16 alphanumeric characters.
1. Log into the Authorize.Net sandbox account at: https://sandbox.authorize.net.
2. Click on Settings under Account in the main menu on the left.
3. From the Security Settings section, click API Login ID and Transaction Key.
4. Enter the Secret Answer to your account's Secret Question.
For production account credentials, use https://account.authorize.net
Yes you can process normal refunds and also submit unlinked refunds on your sandbox account using ECC. Expanded Credit Capabilities (ECC) allows you to issue refunds on transactions more than 120 days old, and issue refunds for transactions that were not processed through your Authorize.Net account. It is enabled automatically on sandbox accounts. ECC is a free feature, but please note that for live accounts, ECC is subject to approval. The account owner or administrator will need to fill out a form to enable this service.
By default, the the maximum transaction size is $100 and the monthly volume limit for eCheck is $5000. Transactions will decline if you try to run a transaction over the default limits.
You can always contact us to request raising these limits.
Solution ID uniquely identifies the software that generates a transaction. Software vendors can create and manage Solution ID within the Reseller Interface and include it in the transaction request API calls. Unlike your merchant referrals, which are tied only to your Affiliate ID, Solution ID identifies the application creating a transaction for every merchant using the software, regardless of who sold the application, payment gateway or merchant account.
Include Solution ID to your transactions following with these simple steps in our Solution ID Integration Guide.