It would definitely look more professional if you were to have a landline number when you are operating a business.
I’m basically looking at either getting Skype or Sonetel. Since most of my operations are currently based in the US, I’m looking to get a US number.
All prices in USD unless otherwise stated.
Cost Factor – Number Subscription
A 3 month subscription for US Skype Number would cost $18.53 after a 5% discount. A 12 month subscription for US Skype Number would cost $52.26 after a 33% discount.

Contrast that with Sonetel, which cost $1.99 per month for a New York number if you sign up for one month. Call forwarding to Singapore cost $0.01 for every minute. Also, Sonetel offers you a free trial.
A 12 month subscription for would cost $1.42/month, bringing it to a total of $17. A 36 month subscription for would cost $0.89/month, bringing it to a total of $32.

Call Forwarding Option
Both Skype and Sonetel offers a variety of call forwarding options. Most of my correspondence with my suppliers are through emails due to the timezone difference between US and Singapore. Hence call forwarding option I’m specifically looking for is call forwarding to voicemail or an automated message.
For Skype, it’s not clear from their FAQ if call forwarding to voicemail will be charged as normal calltime.
For Sonetel, they have indicated in their FAQ that forwarding to a voice app is free, but subjected to a fair usage limitation. Read more about Fair Usage Limitation here.
To summarize :
“Phone numbers that do not have a per-minute-fee for incoming calls and that end up in a Voice app or are answered with some VoIP device are subject to a fair usage restriction. Regular accounts have 1,000 free minutes per phone number and month. Premium accounts have 2,500 free minutes per phone number and month. Over-usage is charged at $0.01 per minute.”
I would say it’s more than enough for what I need it for!
Signing up for Sonetel Trial
Sonetel seem to suit my needs. Signing up for the trial is easy.
Go to http://sonetel.com/en/ -> Click on “Prices” -> Then click “Sign Up & Try For Free” button. You will then be directed to the below page :

Pick your number, click “Try Free”and you will be asked to fill in your details. Do fill in a valid mobile number that you are using as they will be verifying it through SMS.

Click on “Verify My Mobile” once you are ready to proceed. You will next receive a PIN through SMS.
Sonetel Interface
After your account is created, you will come to this interface.
You can see the number you have chosen and also where your calls will go to.

You can click “Change” to change your call forwarding options.
If you do, you will come to this screen below.
From here, you can choose where to connect your calls to. Choose from “Nowhere”, “To a user”, “To a voice application”, “To another destination”, “To SIP”.
To find out more about the various options : Go to Sonetel FAQ : How can I configure a phone number.

I have chosen to connect to a voice application. Generally, that means :
To a Voice application : Connect the phone number to a Welcome menu for callers. A second drop down menu appears for selected Welcome menu (in case you have more than one).
After you’ve chosen, there will be another menu to further refine your option. I’ve chosen for it to go to the “Main menu”.

Go back to the main page. From the main page, you can click to expand the “Voice apps” menu. You can change your Voice application options from there. You can make changes to either the Voice Response App or the Voicemail App.

What is a Voice Response?
From Sonetel FAQ : Each Voice Response app that you create comes with standard, pre-recorded messages – in the language of your preference – that are played to the caller. You can replace these by either recording new messages from a phone, or by uploading voice files.
Since my calls are going to the “Main Menu”, that’s the one I will configure.
Click “Change” on the first row for “Main Menu”. You will get the menu below.

You can configure things like language, actions and also response to the menu selections.
You can also record and upload new messages to play to your callers.
For more on how to configure your voice response, check out what the voice response can do here.
This is how I configure mine :

I recorded a wav file to say : “Thank you for calling XXX. We are currently not able to take your call. Kindly email us and we will get back to you.”
This file replaces the Main Menu, which gives callers the option to press for further action. Since I just need an “announcement” service, I removed all interactive options.
I also unticked the “Play the welcome message” option. This is because I did a test call to the number using my Skype, and the welcome message was oddly out of place. By unticking “Play the welcome message”, all my callers will hear is the message I recorded and uploaded.
For recording your voice messages, you can try Free online Text To Speech (TTS) service. Click here for the one I use. Just type in your message, select language and voice. The file is only available for download in MP3 though.
You can simply use a mp3 to wav convertor to get your .wav file for Sonetel. I used this online audio convertor.
And you are done!