# Support
source: https://developer.mastercard.com/mastercard-buyer-payment-agent/documentation/support/index.md

## FAQ {#faq}

By renewing your key you should be prompted once again to download the P12 certificate and then the DER and PEM certificates will be emailed to you. Initiate a GET request directed at the endpoint, `/buyer-payment-agents/{ica}/payment-instructions/{transaction_id}`. For more information on how to check a payment status, click [here](https://developer.mastercard.com/mastercard-buyer-payment-agent/tutorial/retrieve-payment/index.md). You have three options when it comes to renewing your keys. This [article](https://developer.mastercard.com/platform/documentation/getting-started-with-mastercard-apis/renewing-your-keys/) provides in-depth information on the approaches that you can take. Buyer Payment Agent accepts any valid ISO alpha-three currency code. For more information, refer to the [ISO 4217 Currency Codes](https://www.iso.org/iso-4217-currency-codes.html). A sandbox key is intended just for testing purposes. In the sandbox environment, you can make any changes you want. A production key gives you access to the live production environment. Any changes you make in the production environment will affect customers and needs to be carefully considered. Supplier Payment Agent APIs can be found [here](https://developer.mastercard.com/mastercard-track-supplier-payment-agent/documentation/). A Buyer Payment Agent acts on behalf of a Buyer to submit payment instructions. A Buyer Payment Agent can include acquirers, banks, and other specialty players like accounts payable automation companies and payment facilitators.

A Supplier Payment Agent acts on behalf of a Supplier to retrieve and process payment instructions. A Supplier Payment Agent can include acquirers, banks, and other specialty players like accounts receivable automation companies and payment facilitators.

## Get Help {#get-help}

### Contact us for technical support. {#contact-us-for-technical-support}