QB Issue Resolution:

Add a custom letterhead to an invoice or other transaction template.
Detailed instructions

Although there is no place in QuickBooks to use a letterhead, it is possible to use the logo and Layout Designer as a workaround.

If you have your letterhead in a Microsoft Word or other text type of document, you will first need to “capture” the letterhead and save it as an image file.

If your letterhead is already an image file (.jpg, .gif, or .bmp), then you can skip the first set of instructions and continue to the steps appropriate for your version of QuickBooks.

Save your letterhad as an image file:

Open the document that contains your letterhead, then press the Print Screen key on your keyboard.
Open Microsoft paint or another image editing program (as appropriate to your system).
Press Ctrl + V to paste the picture of your Print Screen within the image editor. Edit as needed.
Once you’ve edited your image, choose the File > Save As option (as appropriate).
Choose a location to save this file, Desktop is fine, and name it Letterhead.bmp.

In QuickBooks:

Choose Lists > Templates.
Select your template from the list, click Templates > Edit Template.
If your letterhead will be replacing the Company Name, Address and Phone number fields on the invoice, then you’ll want to uncheck these fields in the Company and Transaction Information area.
Select Use Logo and browse to your letterhead image file and select it.
Select Layout Designer to resize and reposition the letterhead image.

Other Articles To Try

Adding a Logo or Image to an Invoice Template Causes the Edges of the Images to be Pixilated

Resolution for Issue 'Add a custom letterhead or logo to an invoice or other transaction template.' available: Yes (Solved).
Source: Intuit Community forum.

Add a custom letterhead or logo to an invoice or other transaction template.: this issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the issue yourself by looking for a resolution described below. If it is a complex issue or you are unable to solve the issue, you may contact us by clicking here or by using other support options.

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