Double-check that there are no spaces before or after the expiration date when you enter it.
The credit card expiration date format on an iPhone is MM/YY, regardless of the country. This is the ISO 7813 standard format for credit card expiration dates. The MM stands for the month, and the YY stands for the year. For example, the expiration date of 03/24 would be March 2024.
There are some countries that use a different format for credit cards expiration dates, such as MM-YY or YYYY/MM. However, these formats are not as common as MM/YY, and they are not supported by the iPhone.
If you are entering a credit card expiration date on an iPhone, you should make sure to use the MM/YY format. This will ensure that your payment is processed correctly.
Here is a table of the different credit card expiration date formats and their corresponding countries:
MM/YY or MM/YYYY--> Most countries
MM-YY --> France, Germany, Italy, Spain, Portugal
YYYY/MM --> Japan