How do I associate my account with a specific merchant category code?

[Ridewright]

I need a very specific merchant category code (MCC) in order to accept payment from my customers. I own a vanpool business, and my customers’ debit cards are restricted to only work for merchants who have MCC 4789 - Transportation Services. I selected this category description when setting up my Square account, but cards are still declined. How do I ensure this specific, numerical code is associated with my account?

[VanKalkerFarms]

You can't change it after you register online, but if you call in they should be able to assist you with changing your MC.

https://squareup.com/help/contact

Click "Other"

Click "I don't see my issue"

Click "Call Support"

Write down your Customer Code

Call 1 (855) 700-6000

Depending on your specific account, you might not have phone support available, or you might have limited hours of support. 

if you have a smartphone you can program the phone number with the code into your phone so it will be there next time, store it like this 18007006000,,xxxxxxxxxxxx . (your code goes where the xs are).  The commas tell the phone to wait 3 seconds each and will automatically enter it for you.