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Security & privacy
Activate secure login
Keep your profile secure by setting up MFA so any login attempts from unknown devices require additional authentication.
Read ArticleWhy is my card reader blocked?
If you see "Blocked device", your device's security mechanism has triggered. Here's what to do with blocked card readers and how to prevent future blockages.
Read ArticleLost or stolen card reader
What happens if your card reader goes missing? Here's how to report lost devices and ensure your data is protected and prevent fraudulent use.
Read ArticleDefend against phishing attacks
Prevent the loss of sensitive information by defending against phishing scams that seek to steal and expose your personal information. Here are a few tips on how to protect yourself against phishing.
Read ArticleRestricted businesses
As a regulated entity, we operate under strict requirements imposed by the financial regulator, the card schemes (Visa, Mastercard and American Express) and our acquiring banks, who act as a gateway to the card services.
Read ArticleReduce the risk of chargebacks
The best way to reduce the risk of payment disputes is to ensure customer satisfaction at all times, but you can also take additional steps to take payments securely.
Read ArticlePayment disputes: What is a chargeback?
A chargeback is a request for money after a cardholder questions the validity of a transaction. Chargebacks may also be preceded by requests for information such as retrieval requests or fraud reports.
Read ArticlePayment disputes: Retrieval requests and fraud reports
Retrieval requests and fraud reports are cardholder requests for more information on a transaction. They aren't requests for money, but could lead to a chargeback if the requested information isn't provided.
Read ArticlePayment disputes: Contesting chargebacks
There are a variety of scenarios that could lead to a chargeback and each of them requires slightly different supporting evidence to contest. Here, we’ve compiled a list of common types of payment dispute and how to object them.
Read ArticlePayment disputes: Chargeback procedures
Chargebacks can be stressful. So to help out, here's a guide to payment disputes, including SumUp’s own chargeback procedure, from the first request to the final decision.
Read ArticleRecognise phishing attacks
Phishing is an online scam technique whereby scammers impersonate legitimate organisations or people in order to access sensitive information. The following tips will help you recognise and avoid phishing scams.
Read ArticleWhat is Strong Customer Authentication? (SCA)
3D Secure 2 (3DS2) and Strong Customer Authentication (SCA) are measures put in place to make online payments more secure. SCA verifies a customer's identity before confirming purchases with the intent to reduce electronic payment fraud.
Read ArticleHigh-value transactions
Here’s how to accept high-value payments while reducing the risk of a chargeback or other complications.
Read ArticleHow secure is my password?
If you get a warning that your password is on a known list of common or leaked passwords, you may be at risk to hackers. Here’s what you need to know.
Read ArticleSecurity
Your security is of the utmost importance to us at SumUp. Here, we've collected information on everything you need to know about how we keep you secure.
Read ArticleMerchant security
The security of both your data and that of your customers is our top priority at SumUp. This is what we do to keep it safe.
Read ArticleGDPR, SumUp and my data
At SumUp, we take data protection very seriously. Here's everything you need to know about how we handle your information and keep your data secure.
Read ArticleInvoice inquiry
We are obliged by our payments providers to check the legitimacy of the transactions. We might be required to collect additional information, such as an invoice (in PDF format), from you to verify the payment.
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