How to Buy Lingerie as a Gift Without Knowing Her Size

To buy lingerie as a gift without knowing the size, copy the label from a bra your partner already wears often, buy that exact size, preferably from the same brand, and choose forgiving pieces such as a robe, a slip or a stretch bralette if you cannot check. Ask for a gift receipt, and read the store's hygiene rules before you pay.

That is the short answer. The rest is how to do each step without being caught, and what to do when the label is unreadable.

Read the label on a bra she actually wears

Pick the bra that comes out of the laundry most often, not the one at the back of the drawer. The one in rotation is the one that fits. The size is printed on a fabric tag at the center back, on the side seam, or inside the band near the hooks. Take a photo of the whole tag rather than memorizing it, because there is more on it than you think.

A bra size is a band number and a cup letter: 34C means a 34 inch band and a C cup. Many labels print the same size in several systems. The continental European band is in centimeters in 5 cm steps, so a US and UK 34 is a 75. French, Spanish and Belgian bands run exactly 15 cm larger again, so the same bra can say 90 in France. Copy the number from the system the shop uses.

Cup letters past D are where gift buyers go wrong. UK sizing runs D, DD, E, F, FF, G. American brands follow no single rule: some go D, DD, DDD, some use the UK sequence, some jump to G after DDD. A DD from a British brand and a DD from an American one may not be the same cup. Sizes also vary between makers, so two 34Bs from different companies can fit differently. Buying from the brand on the tag removes most of that risk. If it is Marks & Spencer on the tag, buy from M&S.

Briefs are easier. Most carry a letter (S, M, L) or a dress size, and one tag tells you what you need.

Sister sizes, and when to size up

ThirdLove's fit guide explains sister sizes: bras that hold the same cup volume on a different band, because "the same cup letter holds more on a bigger band." A 34C has the same cups as a 32D or a 36B. Go up one band and down one cup letter, or the reverse.

This is useful if the tag is half washed out and you can read only the cup, or if the brand you are buying from does not make the exact size. It is less useful as a way to guess. If you do not know the band, you do not know the size, and an underwired bra in the wrong size is a return, not a gift.

For everything that is not a structured bra, size up when you are torn between two sizes. A robe one size too big still wraps. A slip a size too big drapes. A brief a size too small digs in, and asking for the next size up is an awkward conversation to start a holiday with.

Which pieces forgive a wrong guess

A bralette has no wire and no molded cups, and most are sold in letter sizes, which is why it is the usual compromise. Do not assume a letter means the same thing everywhere: each brand maps S, M and L to its own spread of band and cup sizes, so read that brand's chart against her label. Our comparison of the bralette and wireless bra covers what each does.

Robes are the safest, because a wrap robe closes with a tie rather than a fixed seam. Slips cut on the bias in satin or silk stretch on the cross grain without elastic. Some one-size thongs give their range in plain words: Hanky Panky's Original Rise thong is sold as one size that fits US sizes 4 to 14.

Gift receipts, hygiene seals and the January return

Ask for a gift receipt at the till or at checkout. It lists the items and keeps the barcode but hides the price. The catch, as a Scripps consumer report put it, is that a gift receipt usually gets the recipient an exchange or store credit, not cash: the refund belongs to whoever paid. Keep your own receipt too.

Lingerie adds a second rule: hygiene. M&S, for example, accepts underwear and lingerie back if the packaging is undamaged, or with tags and hanger still on if it was not packaged, but "items with hygiene seals must be returned with the seals intact." So do not open the seal, cut the tags or try anything on yourself to check.

Holiday timing helps. For the 2026 season M&S says full-price items bought on or after 22 October 2026 can be returned until 17 January 2027, with sale items still held to 14 days, and gift receipt returns taken in UK stores. Other stores set their own holiday windows. Read the one for the shop you are using before you buy, and put the gift receipt in the box.

Last updated October 28, 2026

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