Character Limits for Fields in QuickBooks

Field Maximum Characters
Account Name 31
Account Numbers 7
Amount 20
Custom Fields (Items) 30
Customer Message (Invoices) 101
Customer, Vendor, and Other Names 41
Item and Class Names1 31
Employee Name (First and Last) 25
Item Description (Invoices) 4095
Item Part Number 31
Job Description 99
Memo2 4095
Note Fields3 4095
Notes in Shipping/Billing Address 41
Username 29
Password 16
Ship to Name 41
Invoice Number Field 11
Lot Numbers 40
Report Company Name 60
Report Title 60
Report Subtitle 60
Report Extra Footer 60
Text Box 1000
PO Numbers 25

1 Item name may contain special characters, but it is recommended that the first character not be a special character.

2 While the Memo field may contain 4095 characters, only 30-60 characters will display on printed checks depending on print settings. 96 characters will display on a Transaction Detail Report.

3 While the Notes field on the timesheet can contain 4095 characters, only 96 characters will display on the Time by Job Detail report.

Source: Intuit QuickBooks Community