- For Next Day Delivery, please place your order before 1pm GMT (Monday-Thursday) to receive it on the next business day.
- For Standard Delivery, shipping will take 4 - 6 business days
- For non-mainland UK addresses, please allow up to 5 business days to receive your order
**Shipping times may be affected by busy sales periods such as the holiday season.
To guarantee your order to arrive in time for Christmas, please order before:
- 20th of December for Standard delivery with Royal Mail
- 21st of December for Next day delivery with DPD
If you are shipping to an address in London, you can take advantage of our same day or next day delivery service, which will be delivering up to the 24th of December.
Next Day: £2.99
Same Day: £3.99
Select a delivery window or get it before 9am: £4.99
Powered by Quiver, faster, emissionless delivery
Small orders of 4x Briefs or less sent with Royal Mail will fit through your letter box. This service has limited tracking and tracking will only update once they have attempted to deliver your order.
Larger orders sent with standard delivery or Next day delivery are fully traceable .
All of our styles fit true to size. On each product page there is a size guide which we would recommend taking a look before making your choice.
We have made returns easier thanks to our onlinereturns portal.
All you will need is your Order number (found on your order confirmation email) and email address. Please review our returns policy before submitting a return.
And please note, we reserve the right to adjust your return method if your return arrives in a condition that does not comply with our returns policy.
We are happy to accept returns of items based on the conditions outlined below.
- You have 30 days from the date your order is despatched to return your order for a refund, exchange or store credit.
- We expect to receive your order in the same condition it was delivered in, with hygiene sticker intact and swing tag attached. The item must be unworn and unwashed.
- We reserve the right to adjust your return method if your return arrives in a condition that does not comply with our returns policy.
- Please allow up to 14 business days for a return or exchange to be processed once it arrives at our warehouse and is inspected. You will receive an email from us when the return or exchange is processed.
- Items purchased in seasonal sales (using a promotional code or discount) and complimentary items are not eligible for returns.
- Please note refunds on return goods do not include the value of shipping.
We are based in the UK and offer international shipping to the USA.
US: Standard Shipping £11.5 (5 - 7 working days) / Express Shipping £26 (2 - 10 working days)
Please note, shipping prices vary at checkout.
Items shipped outside the UK may be subject to import duties and taxes applicable to your country or country you are shipping to. Customers are solely responsible and liable for any duties or VAT that are specific to their country. We recommended that you contact your local customs office for further information.
For international orders outside of the UK, please note that we do not currently accept returns.
All major credit cards and payment methods are accepted, including Mastercard, Visa, American Express, Apple Pay, PayPal and Klarna.
Of course, you can either text us on +447888300084 or get in touch via team@theunderdays.com
Items purchased in the sample sale are final sale and are not eligible for refund or exchange.
We recommend washing all our underwear on a cool wash, maximum 40 degrees.
If you have purchased items that are in stock and a pre-order item(s), the items in stock will be despatched immediately and the pre-order item will be despatched once restocked.
All international orders that include a pre-order item(s) will be held until the pre-order item is restocked.
All customers will be charged for the pre-order item(s) once the item is restocked and fulfilled.