Hello!
Please I have this issue of my card being declined while trying to make payment for my plan and this same card works perfectly fine on other websites.
Hi, @BiokeFatimoh
Welcome to the Shopify Community.
It sounds like you are potentially using a pre-paid credit card which is not accepted by Shopify. Pre-paid cards generally work for making online purchases, but not for subscription services such as Shopify.
If you are using a traditional post-paid card, you will need to contact your bank to determine why the card is being declined.
Best of luck!