Square Invoices is the best service that I have found for what it does: it's easy to use, nice to look at, and never seems to go to spam or be lost by clients. Clients mention that the setup is easier than services my competitors use. You can even attach your contract to the invoice, which is wonderful in case there are questions later on. Unfortunately, not being able to have clients alter quantities or select add-ons means for half of my services, I have to use a different, inferior service.
The only time I had a problem was a false chargeback from a client. Square Invoices referenced our contract and ruled in my favor, and they did so in a timely manner. I sent them the contract and my email history with the client, and they quickly unfroze the amount of money.
I feel that for what it does, Square Invoices outperforms its competition. Because we have used the program for several years, we have seen how they continue to improve their service - making it user-friendly and accessible for a variety of needs. Other platforms are not as easy to set up, add items, and access funds after payment is received.
The fee for invoicing is extremely reasonable for how easy it is. At 2.75% per transaction, it's well worth it.
I like that invoices can be printed and mailed or sent via email for easy online payment.
I have a 100% collection rate on my invoices, and they are often paid within 24-48 hours of being sent, which saves me the time of chasing down checks, which can be especially cumbersome when I have multiple clients.