It took a few really hard knocks, but I finally learned my lesson:
Rule #1 EVERY job gets a job number and a completed work order sheet...EVERY job....NO EXCEPTIONS!
Rule #2 Enjoy life...because you followed rule #1 EVERY time. It's hard to invoice for something if you don't have a paper trail.
I made my work order sheet in Excel and it includes an area for the job number, the date the order was taken, the due date, quoted cost, invoice number, job completion date, ship date, purchase order number, complete customer contact information, description of the work to be done, and a spot to rubber stamp payment information. Yep...I also keep track of payment info on the work order also.
The Excel file contains an invoice and a packing list that are automatically filled out when the work order is filled out.
When the job is completed, the work order is paper clipped to the invoice and placed in an accounts receivable binder. When payment is received, the invoice and work order are noted accordingly and each is filed away in a separate binder. Every work order is traceable to an invoice, and every invoice is traceable to a work order.
At the end of the year, I have a binder full of work orders and a binder full of invoices for future reference.
All of this same information is stored on the computer as well, and is backed up for archival purposes in case of a disaster...or if a customer calls...I can have my hands on the information in about twenty seconds....even past orders and invoices.
It takes a lot of work to keep well organized, but your accountant will thank you greatly...and you'll enjoy your business a whole lot more.
On a further note, everything is color coded so when I see a stack of papers on my desk, I instantly know what's there: quotes are orange, work orders are green, purchase orders are yellow, inventory sheets are pink, expense sheets are light blue and invoices are white. Yeah...that's a lot of paper to keep on hand, but it really saves a ton of time when it comes time to track down a particular document on my desk, or in the shop.
I can't take credit for this idea, but this is what Michael Gerber (in his book "E-Myth") calls a business "system"...a pre-planned method for doing things.
PS....my first "filing" system consisted of shoving a stack of papers in a clasp envelope, scribbling a few notes on it...and stuffing it into the filing cabinet...never to be seen until tax time.
JB