We see a lot of files that are intended to bleed, but do not actually bleed. We are here to help?
First, what even is bleed?
Here is an explanation from Binders Inc.:
In the printing world, bleed is a very important concept that deals with the edges of paper and how it is printed or cut. Since printers essentially grab each sheet of paper by the edges to feed it through the printer, no printer is capable of printing all the way to the outer edge of the material.
In addition, paper and other material is often printed at a very high speed, which can cause it to not feed through the printer in exact perfect alignment—even when using a professional printing service.
If you print words, logos or images all the way to the edges of your template, they will likely end up appearing slightly cut off in the final product. Understanding bleed margins help prevent this problem by expanding the text or image outside of the designated printed area, resulting in a polished and professional final product.
A little further..
A standard bleed area is generally .125 inches on each side. So, if you’re preparing a standard 11 x 8.5 inch document for printing, you will want the final template to actually be 11.125 x 8.625 inches. Or if you’re printing a custom background image on a on a standard 9 x 12 inch folder, the image should extend to at least 9.125 x 12.125 inches for each side.
Most common document only require a .125 inch margin; however, larger documents may require a larger bleed area. The standard bleed area for documents larger than 18 x 24 inches is generally .5 inches. For example, if you want to prepare an 18 x 24 inch document for printing, you will want to prepare an 18.5 x 24.5 inch template. Remember to also leave room for cutting.
There’s no way to be sure exactly where the bleed area will be cut, so be sure to extend images beyond the edge of the final document and all the way to end of the bleed zone. For instance, it would okay to extend a background design into the bleed zone, but you wouldn’t want to have a photo of someone in the bleed area or else you risk them getting cut from the final design.
To summarize, the correct way to send is files that are supposed to print to the very edge, even just one image or page in a zine, your size should not be 5.5x8.5”, it should be 5.75x.875” if you include .25” bleeds. We need at least .125” and if you do not include it we enlarge your page to make it for you. This means: a lot more work for us, but more importantly some of your image you intended to print will be cut off to make a bleed.
How to include and export bleeds in Photoshop:
The easiest way is to make your document size larger, and draw guides for yourself for the trim.
The correct way to add bleed to your document is to choose “File,” then “New,” to start a new document. Set your new document's size and resolution. Remember to add the size of the bleed to your document size. For example, if your final document size will be 5 by 7 inches, and the required bleed is a quarter of an inch, you should set the document width to “5.25 inches” and the height to “7.25 inches.” Finally, click “OK” to create the file. To edit an existing file, go to “File,” and “Open,” then select the file and click “Open.” Choose “Image,” then “Canvas Size,” and increase the width and height of the canvas to include the bleed. Click “OK.” You will see a border filled with the background color around the edge of your document.
How to include and export bleeds in InDesign:
How to create a PDF that includes bleeds:
If you know your design will extend to the paper’s edge, you can set up the bleed area right when you create your document.

Upon launching InDesign, click Create new. (See Create a new document to learn more about customizing your new document.)
Select the Print tab at the top. In Preset Details, choose your preferred measurement units.
Scroll, and then click Bleed and Slug to expand the panel. Type a bleed value in any units. For example, you can type 0.125 in or 3 mm even if your document uses picas or something else. Set the same bleed on all sides, or click the chain icon to set different values for the top, bottom, inside, and outside settings.

Note: Bleed values of .125 in (3mm) are standard, although some print providers may require a larger bleed area. 

Optionally, you can include job notes and instructions for your printer in a slug area that typically extends beyond the bleed area. The slug is also trimmed off.