Is it possible to search my customer database by town/zip code ?

Yes, it's possible, levco1.

We can do this by using the Search function in QuickBooks Online. I'll guide you how.

1. Go to the Sales menu.
2. Choose the Customers tab.
3. On the Search field, enter their zip code.
4. Click the magnifying glass. 
5. Then, select the name of the customer.

You also easily search transactions with the help of this feature: Use the Magnifying Glass.

I've also included an article that'll help you keep track of your sales and inventory status in QuickBooks: Run Reports.

Feel welcome to get back on this thread if you'll need assistance in dealing with your sales transactions. I'm always here to help you. 

I tried what you suggested..... entering a zip code into the search bar and then clicking the magnifying glass....it did not work. Please advise. 

Good morning, @levco1. 

These steps should have worked in your account. However, rarely glitches occur in the system and need just a few troubleshooting steps to help resolve the issue. 

Using a private browser or incognito window can help eliminate this glitch to fix this problem. Here's how depending on your session:

• Safari: Command + Shift + N
• Internet Explorer/Firefox: Ctrl + Shift + P 
• Google Chrome: Ctrl + Shift + N 

If this works, then go back to your regular session and clear your browser's history. This will allow QuickBooks to load as a fresh new page. If this doesn't work, then I suggest contacting our Customer Support Team. They'll be able to use some more advanced tools to walk you through additional steps. 

Let me know if this helps or if you have to request a callback. I want to make sure that you're taken care of. I'm only a post away if you need me again. I'll be back around shortly.