Welcome to the Underdays Circle

Our affiliate programme built for creators who genuinely love what they wear.

At Underdays, we believe wellness starts with what you wear closest to your skin. We're building a community of creators who share that belief, and want to build something real with us. The Underdays Circle is our affiliate programme. Join and earn commission on every sale you drive, while getting early access to launches, community support, and a clear path to paid partnerships.

How To Get Started

STEP 1

Complete your Circle profile

Fill in your details using the link below. Takes two minutes. Your welcome email lands straight after with everything you need to get started.
Step 2

Claim your welcome gift code

Your welcome email includes a personal 15% off code to try Underdays for yourself. Head to the site, choose your style and size, and apply at checkout.
STEP 3

Connect on ShopMy or LTK

Your welcome email includes instructions to connect with Underdays on ShopMy or LTK — or both. Once connected, your affiliate link is live and you start earning 15% commission on every sale.
STEP 4

Earn your Welcome Starter Kit

Drive 3+ orders from your audience through your affiliate link within your first 30 days and we'll send you a physical welcome starter kit — 3 x underwear and a scuba pouch, on us.
STEP 5

Grow with us

The more you post and sell, the more you unlock. Higher commission rates, early access to launches, event invites, and paid content opportunities await our top creators.

Not sure where to start? Meet our bestsellers

SHOP NOW
model_info=model wears size s

The Everyday Thong - Teddy

£18 GBP

New

model_info=model wears size s

The Everyday Boyshort - Teddy

£22 GBP

New

model_info=model wears size m

The Workout Thong - Vintage Blue

£18 GBP

model_info=model wears size m

The Tank - Vintage Blue

£38 GBP

model_info=model wears size s

The Everyday Thong - Teddy

£18 GBP

New

model_info=model wears size s

The Everyday Boyshort - Teddy

£22 GBP

New

model_info=model wears size m

The Workout Thong - Vintage Blue

£18 GBP

model_info=model wears size m

The Tank - Vintage Blue

£38 GBP

SHOP NOW

The Tiers

STANDARD

Commission: 

15%


Threshold: 

Any sales


Highlights: 

15% commission, 15% off welcome gift code, starter kit gifted when your audience drives 3+ orders within 30 days, WhatsApp community, monthly best-practices email

TOP PERFORMER

Commission: 

18%


Threshold: 

£2000+/$2500+ / quarter


Highlights: 

Everything in Standard, plus: 18% commission, quarterly creator event or team call (by region, early access to launches, performance feedback from the team

HERO

Commission: 

18%


Threshold: 

£5000+/$6500+ / quarter


Highlights: 

Everything in Top Performer, plus: automatic consideration for paid UGC campaigns — Hero creators are first in line every time we brief paid content

Ready to join?

Click the link below to get started.

Join the Underdays Circle

@theunderdays

Follow on Instagram