Why is my sewing machine skipping stitches?

Skipped stitches mean the hook missed the loop of top thread. In the great majority of cases, the needle is why.

Wrong needle type for the fabric. On knits, a universal point pierces the loop of yarn instead of sliding between the yarns. The loop is cut, the hook finds nothing to catch, and you get a skipped stitch. A jersey needle fixes this outright and it is the first thing to try on any knit.

Blunt needle. A rounded tip deflects slightly on entry, which moves the loop out of the hook’s path.

Needle not fully seated, or fitted the wrong way round. Push it all the way up into the clamp and check the flat of the shank faces the direction your manual shows.

Then, less often: top thread not properly in the tension discs, so the loop never forms cleanly; or the fabric flagging — bouncing up and down with the needle — because the presser foot pressure is too low or the fabric is unsupported.

Rarely, timing. If a new correct needle, correctly fitted, still skips on ordinary woven fabric, the hook may be out of adjustment. That is a workshop job and it is the last thing to suspect, not the first.