How to replace a zip in jeans

Plus trousers and shorts – any style with a fly front

I wear these denim shorts all year round, adding tights for the winter. All of this wear has started to show. The inner thigh needs patching and worst of all the zip has broken. I’ve repaired it several times by running a charcoal pencil over the zipper feet (only works with metal zips). This time there was no putting it off, I had to replace the zip.

It is a fairly difficult and time consuming job. Follow these step by step instructions and you too can replace a zip in a pair of jeans, shorts, trousers or skirt. Any style that has a fly front. That means the zip is hidden behind a piece of fabric and it has a zip guard. Which is another piece of fabric that sits behind the zip. Preventing the skin from getting caught in the zip.


basic sewing kit for clothes mending repairs
  • Seam ripper / unpicker
  • Dressmaking pins
  • Sharp scissors
  • Sewing needle and thread in a bright colour (for tacking / basting the zip in place)
  • Sewing thread to match the colour of your garment
  • Sewing machine (if you are based in London and don’t have a sewing machine, book in for one of our workshops where we have several machines for use and can show you how to use one).
  • New zip – Measure the size of the old zip to get the right length. Measure along the zip feet rather than the tape.

How to instructions

The first and most important job is to take photos of how the zip is inserted into the garment. Put stickers on the pieces if necessary. If you do this before unpicking the stitches, it will help you put everything back in the correct place.

how to replace a zip in jeans trouser shorts and skirt with a fly front

Here are the finished shorts. I also patched the inner thighs by using the sewing machine. Find out how to patch your jeans here.

I decided to dye the shorts as they were looking very faded. I had a couple of items of clothing to dye at the same time. I used Dylon’s jeans blue machine dye using the instructions. I’m really pleased with the result and they are my staple piece of clothing for this hot weather we are having.

Denim patching kit available on our Etsy shop

denim jeans patching sewing repair kit