Secure online credit card processing in real-time is outsourced to a merchant payment service provider called Ingenico (previously Ogone) https://payment-services.ingenico.com/int/en
Because of the complexity of the matter and to guarantee the highest level of security, outsourcing online payment transactions is common practice and relates to virtually any payment transaction you encounter on the web.
It is a common issue though that a certain number of online credit card transactions would fail - sometimes the reasons for failure of a transaction are obvious (wrong card number, card limit reached, ...) sometimes the reasons are less obvious and may relate to fraud prevention and/or other security measures implemented by credit card companies.
Every single possible reason for transaction failure though is strictly beyond ISHS control and ISHS - in its position as the beneficiary of the transaction - is not even receiving feedback from the respective credit card companies as to what exactly may have caused a transaction to fail.
This means that unfortunately ISHS cannot really assist in solving the issue which is strictly a matter between the card issuing credit card company (who refused to authorize the transaction) and the credit card holder (who initiated the process to have the amount of the transaction charged to his/her credit card).
In case of a transaction failure, ISHS recommends to first try using an alternative credit card, or to give it another try with the same credit card again but at a later time. In most cases this would solve the issue.
Do carefully check the card details before confirming the transaction for processing. Alternatively try using PayPal instead (know that PayPal allows you to have the transaction charged to your credit card).
Should the transaction continue to fail and before moving over to slower and/or more expensive 'offline' payment methods such as a wire transfer in the ISHS bank account (contact ISHS for details or to request an invoice) you might want to get in touch with your credit card company first. Your credit card company will be able to check the transaction log for your credit card and help fix the problem.
A list of common reasons why payments fail:
*Your credit card limit was reached (insufficient funds)
Check your credit limit. You might have reached your daily or total credit card limit on the day you tried to charge your card. If this is the case, ask your credit card company to increase your limit.
*The charge exceeded the maximum amount allowed for a single charge
Check the maximum amount your card can be charged at a single time. If the declined charge is higher than this amount, ask your credit card company to increase the limit.
*Your card reached the maximum number of charges allowed in a period:
Check how many times your card can be charged in given time period. If you reached this amount, ask your bank to increase the limit, wait until your card can be charged again, or make a payment with a different payment method.
*Your card doesn't accept charges from an online source
Make sure your card allows online transactions. If it doesn't, talk to your credit card company about allowing these charges. Or use another card.
*Your card doesn't allow international transactions
If you're making payments from abroad, make sure your card accepts international charges. If it doesn't, ask your bank to change this or use another card.
*Wrong expiration date
Review the expiration date on your credit card. If your card expired, use another card
*Wrong credit card number
You should get an error message indicating the card number is not valid. If not, carefully check the card number when filling out the form.
Make sure that the billing address you use for the transaction matches those that your credit card company has. Address matching is however not very likely to be the main cause of a transaction failure.