For my small business, we use VOIP.ms for our VOIP provider and equipment. It's been great for us because it's affordable and reliable. They offer a wide range of features and their customer service is top-notch. Overall, we've had a really positive experience with them. If your client is looking for a VOIP provider, I'd definitely recommend checking them out.
Also, I recently came across some points about using call tracking CRM that could be pretty helpful. It's all about keeping track of your calls and customer interactions, which can be super useful for improving customer service and tracking leads.