To sew in-seam pockets, sew a pocket bag to the side seam edge of the front and of the back between the pocket notches, press the bags outward, then sew the side seam in one continuous line: down to the top notch, around the pocket bags, and on down from the bottom notch. Clip the back seam allowance at the two corners so the seam can be pressed open above and below while the pocket lies toward the front.

The pattern pieces for size EU 38 / US 6, drawn by Sewly's drafting engine (seam allowances included). A-line skirt →

How an in-seam pocket works

An in-seam pocket hides in the side seam: from the outside you see only a gap in the seam where your hand goes in. It is made of four pocket bag pieces, a pair for each side, one sewn to the front and one to the back. On Sewly patterns the pocket bag is a single piece labeled "Cut 4 (pairs)", and two notches on the side seam of the front and back mark the top and bottom of the opening, 16 cm (6 1/4 in) apart, which is comfortable for most hands. The A-line and gathered skirts, the shift and fit-and-flare dresses, and the pull-on trousers and shorts all offer it.

Where should a side pocket sit?

The opening should start where a relaxed hand reaches the side seam without lifting the shoulder. On Sewly patterns it starts 6 to 7 cm (about 2 1/2 in) above your hip line, which on most adults is 10 to 15 cm (4 to 6 in) below the waist. If you have long or short arms, check it on a toile: mark where your hand naturally goes in and move the two notches together.

Choosing the pocket fabric

  • Self fabric (the same as the garment) is simplest and stays invisible if the pocket gapes. Fine for light and medium fabrics.
  • Lighter pocketing (cotton lawn, poplin, lining) reduces bulk in thick fabrics such as wool, corduroy and heavy linen. To hide it, cut a 5 cm (2 in) wide strip of the main fabric and sew it along the opening edge of each bag first, as a facing.
  • Knits: pocket bags in the same knit work well. Sew them with a narrow zigzag or stretch stitch.

How to sew in-seam pockets, step by step

  1. Transfer the notches. Snip the pocket notches on the side seams of the front and the back, and on the straight edge of each pocket bag. See notch.
  2. Stabilize the front opening. Optional but worth it: fuse a 1 cm (3/8 in) strip of stay tape or interfacing along the front pocket opening on the wrong side, in the allowance next to the seamline. It stops the opening from stretching with use.
  3. Finish the raw edges. Zigzag or serge the side seam edges of the front and back now, while they are easy to reach. See finishing seams without a serger.
  4. Sew the bags to the front. Place a pocket bag on the front, right sides together, straight edges aligned, notches matching. Sew at 1 cm (3/8 in), slightly less than the 1.5 cm (5/8 in) side seam allowance, so the joining seam will roll to the inside and the bag will not peek out.
  5. Understitch the front bags. Press the bag away from the front, with both allowances toward the bag. From the right side, stitch on the bag 2 to 3 mm (1/8 in) from the seam, through the bag and both allowances. This understitching keeps the bag rolled to the inside.
  6. Sew the bags to the back. Repeat step 4 on the back. Understitching is optional here. Press the bags outward. Press at about 200 °C (390 °F) for cotton and linen, 150 °C (300 °F) with a press cloth for wool and viscose.
  7. Pin the side seams. Place the front and back right sides together, matching the side seams, the notches and the edges of the pocket bags, so each pair of bags lies flat on top of each other.
  8. Sew the side seam around the pocket. At 1.5 cm (5/8 in), sew from the top of the side seam down to the upper pocket notch. Pivot with the needle down, sew around the pocket bags, pivot again at the lower notch, and continue down the side seam to the hem. Shorten the stitch to 1.5 mm (about 16 per inch) for 1 cm (3/8 in) either side of each pivot for strength.
  9. Clip the back allowance. On the back side seam allowance only, clip diagonally into the corner at each pivot, up to the stitching but not through it. This lets the side seam be pressed open above and below the pocket while the pocket turns toward the front.
  10. Finish the bag edges together with a zigzag or serger, all the way around the curve.
  11. Press. Press the side seam open above and below the pocket and press the pocket bags toward the front of the garment. Check from the outside that the opening lies flat and closed.
  12. Secure the top. If the bags reach the waist, baste them to the front waist edge so they are caught in the waistband or casing. If they stop below it, as on Sewly patterns, bar-tack the top and bottom of the opening from the inside, through the allowances only.
Tip: Try the garment on before sewing the waistband and slide your hands in. If the opening sits too high or too low, it is still easy to move.

Pockets and side zips

A side zip and a side pocket compete for the same seam. If your skirt or dress closes with a zip in the left side seam, put the pocket only in the right side seam, or move the zip to the center back so both side seams are free. On garments with a pull-on elastic waist, such as pull-on trousers and gathered skirts, there is no zip to worry about and both sides can have a pocket.

How deep should the pocket bag be?

Deep enough to hold a phone without it sliding out when you sit: a bag about 24 cm (9 1/2 in) deep from top to bottom suits most adults, and that is the depth of Sewly's pocket bag. A bag that is too shallow is the most common regret with in-seam pockets, and it is easy to lengthen the bag on the paper before cutting.

Common mistakes and fixes

  • The pocket bag shows at the opening. The bag was sewn at the full seam allowance, or not understitched. Unpick, sew the bag again at 1 cm (3/8 in) and understitch, or add a facing strip of main fabric.
  • The side seam will not press flat. The back allowance was not clipped at the pivots. Clip it now, carefully, up to the stitching.
  • Holes at the corners of the opening. The pivots take all the strain. Reinforce them with short stitches or a small bar tack, and add stay tape along the front opening.
  • Pockets pointing to the back. They were pressed the wrong way before the waist was finished. Unpick locally, flip them forward, and baste them to the front.
  • Bulky hips. The bags are in a thick fabric. Recut them in a lighter cotton, with a strip of main fabric at the opening.

In-seam pockets are an easy upgrade to the A-line skirt and come as standard on the pull-on trousers. They are also one of the details Sewly looks for when you make a pattern from a photo of a garment that has them.