One of the best ways to add to your credibility is to provide your clients with professional looking invoices. These days, you can find several very powerful, yet easy-to-use web-based time-tracking and invoicing programs that provide different levels of customization and functionality.

Depending upon the volume of work you do, these web-based solutions range anywhere from free for limited invoicing to about $160 a month for high-volume billing.

For most solo entrepreneurs and small businesses, expect to pay anywhere from about $15 to $50 a month.

However, if you only have one or two clients who pay all the bills you might be able to get away with free service from a couple of these sites.

I limited the review to those products that are completely web- and subscription-based. Products I left out include:

• desktop software
• software with platform-specific requirements
• products or services that are add-ons to web-hosting services
• products that are primarily help desk software with a billing feature
• invoicing products specifically for online auction transactions
• products requiring installation and configuration of perl, python, or other scripts, configuration of cron jobs or other functionality

The products are listed in alphabetical order.

Billing Orchard Includes a 15-day free trial with registration. Prices range from $14.95 up to $69.95 per month, plus $10 a month for optional support. Features include recurring invoicing, PayPal integration, Authorize.net integration. According to their website, the product is aimed at web hosts and hosting resellers, lawyers, web developers, consultants, and others requiring time-based and recurring client management.

Blinksale Includes a free version with registration and minimal client invoicing per month. Prices range from free up to $49 per month, depending on volume. Includes recurring invoicing, payment acceptance, BaseCamp integration. According to their website, the product is for any individual or company that needs to invoice customers.

FreshBooks Includes a free version with registration. Prices range from free up to $149 per month depending on volume. Includes recurring invoicing, acceptance of online payments, and mailed paper invoices for a postage fee of a little over $1 USD. According to their website, the product is for any individual or company that needs to invoice customers.

Simply Bill Provides a 30-day free trial with registration. Prices range from $5 up to $25 per month depending on volume. Includes recurring invoicing, time tracking. The product seems to be aimed at solo entrepreneurs or very small companies.

Time59 Provides a 30-day free trial with registration. Price is a flat $19.95 per year. Includes recurring invoicing, online payments, time tracking. Aimed at independent consultants but useful for any solo entrepreneur or small business.

Toad Time Includes a 30-day free trial with registration. Prices range from $9.95 up to $159.95 per month depending on volume. Includes QuickBooks integration, recurring invoicing, time tracking. Seems to be aimed at consultants, independent contractors, web designers, and graphic artists.