You can use online vendor payment for all your suppliers, whether they accept electronic payments or not.
If the vendor accepts electronic payments, your financial institution's payment processor transmits it for you. You can include additional information with the payment, such as the invoice number, invoice date, discount, and a memo, so the vendor knows which bill to apply the payment to.
If the vendor doesn't accept electronic payments, your financial institution's payment processor creates and mails a physical check for you instead. You still save the time and hassle of writing, addressing, and mailing the check yourself. Remember to add about five days' lead time for processing and sending a physical check.