Clients taking their time paying your invoices? You aren't alone. Eighty percent of small-business owners struggle with getting paid on time.

The cost of late invoices:

• 20 percent of small-business owners say they had to cut back on marketing.
• 23 percent say they couldn't afford new equipment.
• 79 percent say they put off paying themselves.

To get your invoices paid on time, use these invoice management tips:

1. Set clear deadlines on your invoices

Your clients should know exactly when they need to pay. Consider adding a penalty for late payments. Do your research on what makes a realistic deadline, to maintain that all-important good relationship with the client.

2. Build rapport with clients

If your clients like you, they'll feel bad for paying late. They also won't forget about your bill if you regularly stay in touch.

3. Automate your invoice process

Keeping track of invoices takes time and some can slip through the cracks. Invoice management software can put together your invoices, send them out to clients and let you know when clients are late.