How to Tell If a Suit Needs Alterations Before You Buy It

A well-cut suit should sit quietly on the body. There should be no pulling across the chest, no collar standing off the shirt, and no trousers pooling over the shoe. Most ready-to-wear jackets are cut for a factory pattern, not for your shoulders, so a modest amount of work is normal. The skill is knowing which faults a tailor can correct cleanly, and which ones mean you should choose a different size or a different cloth.

Jacket: collar, shoulder and chest

Start with the jacket on, buttoned, arms relaxed at your sides. The collar must lie against the shirt without a gap at the back of the neck. A small gap can often be taken out through the upper back or by adjusting the shoulder pitch. A large gap usually means the block itself is wrong. Look next at the shoulder seam: it should finish at the end of your natural shoulder. Cloth hanging over the arm is difficult to hide; a jacket that is short in the shoulder is rarely worth the work, because there is nowhere to add cloth.

The chest and waist tell you how much the body of the jacket can move. You should be able to place a flat hand between the buttoned front and your shirt. If the fronts pull and the buttons strain, you need a larger size. Taking out a jacket that is already tight seldom looks as clean as buying the next size and reducing the sides. Surplus at the waist, by contrast, is routine work — provided the factory left enough seam allowance, which many high-street suits do not.

Sleeves, trousers and what to bring

Sleeves should reveal about a centimetre of shirt cuff. Ready-to-wear sleeves are often long. Shortening them is straightforward unless the vents and working buttons sit too close to the hem. In that case the cuff has to be rebuilt, which takes more time and should be priced before you commit. Trousers are more forgiving than jackets. Rise, seat and thigh should feel comfortable when you sit as well as when you stand. Length is set to the shoes you will wear with the suit, not to a generic break. A heavy break can be lifted. A hem that is already short cannot be let down unless the original allowance is still inside the leg.

Bring the shirt, the belt and the shoes you plan to wear. At our Pimlico atelier we pin jacket and trousers together so you can see the finished line before we cut. If the bones of the suit — shoulder, collar, chest — already sit well, alterations will refine it. If those bones fight you in the changing room, walk away. No amount of taking in will turn the wrong block into a well-fitting garment.