We offer the following delivery methods:

Standard Delivery: $8 (free over $75)

Express Delivery: $28

We aim to fulfil your order within 1 -2 business days. During peak periods or sales, processing times may take a little longer - up to 7 business days.

Standard Delivery: 3 - 5 business days

Express Delivery: 1 - 2 business days

Please note transit times are estimates and not guaranteed.

**Shipping times may be affected by busy sales periods such as the holiday season.

Of course, please get in touch via team@theunderdays.com.

Please notify us of any changes as soon as possible. We’ll do our best to accommodate your request, but we can’t guarantee changes can be made once your order is in processing. If your order has already been despatched, changes cannot be made.  

Yes, we do — please visit our UK website to ship to the UK, Australia, or Europe.

Australia:

Standard shipping £15 / Free over $250 (2 - 5 working days)

Express shipping £24 (2 - 3 working days)

France, Ireland, Netherlands:

Standard shipping £9 / Free over 150EUR (2 - 5 working days)

Express shipping £10 (2 - 3 working days)

Denmark, Sweden, Italy:

Standard shipping £9.50 / Free over 150EUR (2 - 5 working days)

Express shipping £12 (2 - 3 working days)

No. All duties and taxes are included at checkout — there are no additional charges after placing your order.

No, only one discount code can be applied at one time.

We accept returns on eligible items under the following conditions:

• You have 30 days from the dispatch date to request a refund, exchange, or store credit.
• Items must be unworn, unwashed, and returned in their original condition, with the hygiene sticker intact and swing tag attached.
• Refunds exclude original shipping charges.
• Please allow up to 14 business days from the date your return is received for it to be processed. We’ll notify you by email once your return or exchange is complete.
• If an item does not meet our return conditions, we reserve the right to amend the return outcome accordingly.
• Items purchased during the Black Friday sale remain eligible under our standard return and exchange policy.

To initiate a return, please visit our US Returns Portal within 30 days of dispatch:

👉 theunderdays-us.loopreturns.com

All sales are final 30 days after the dispatch date.

Yes, we've extended the returns period for all purchases made from the 10th of November to the 24th of December to be returnable up to the 16th of January 2026.

Orders that include a pre-order item(s) will be held until the pre-order item is restocked. You’ll receive an email with the estimated despatch date once your pre-order is placed.

All Underdays styles run true to size. Each product page includes a size guide— we recommend checking this before placing your order.

We recommend washing all our underwear on a cool wash, maximum 104°F and preferably in a garment bag.

• Air-dry flat in shade.
• Do not iron or tumble dry.

We’re not perfect but we’re working on it. Click here to read more about our sustainability plans.