Internet service providers should fall into MCC 4816 according to the Visa reference (https://usa.visa.com/content/dam/VCOM/download/merchants/visa-merchant-data-standards-manual.pdf). However, we recommend that you validate these merchant details by first completing a transaction with a Marqeta-issued card so you can easily examine the transaction data. You would have to generate a card in a production environment in order to transact with the merchant.
Once you've confirmed the MCC that this merchant is using, you can specify that MCC in the 'merchant_scope' object of the velocity or authorization controls that you create:
Whether you use velocity or authorization controls to implement your spend controls will depend on whether you're using a JIT funding gateway to approve transaction in real-time, and the configuration of your Marqeta environment. Please reach out to your Marqeta representative if you'd like to clarify the implementation approach for your specific use-case and environment configuration.