Use an affiliate link when your audience can tap and buy in the same session, and a discount code when they are likely to buy later, on another device, or after hearing about the product somewhere a link can't go. Many deals use both, because a link records the click while a code is recorded at checkout, and each one covers gaps the other leaves.
How each one decides whose sale it is
An affiliate link carries an identifier. When someone taps it, the retailer or network drops a cookie or a similar marker, and a purchase inside the program's attribution window is credited to you. The chain is more fragile than it looks. LTK's help article on commission and cookies spells out the weak points: windows vary by brand, the marker does not survive a move to another browser or device, and a later click on another affiliate's link takes the credit.
A discount code works at the other end of the journey. It is credited when the shopper types it at checkout, however they arrived, which is why codes suit podcasts, videos without clickable captions, events, and anyone who researches on a phone and pays on a laptop. The UK advertising regulator's affiliate marketing advice describes both methods side by side, noting that clicks or purchases are counted through discount codes or URLs unique to each affiliate.
The two can also collide. LTK's article names a one-time promo code entered at checkout, such as a newsletter sign-up discount, as one way a link loses credit for a sale. If a deal pays you through both methods, agree in writing which one wins when a shopper uses your link with someone else's code, or your code after someone else's link.
Decision table: link, code or both
Start from where your audience meets the recommendation and how they tend to buy, then check the catch before you commit.
| Where the recommendation appears | Lean towards | Reason | The catch |
|---|---|---|---|
| Instagram Story with a link sticker | Link, with a code as backup | One tap takes the viewer straight to the product page | A Story carrying an organic link sticker cannot later become a partnership ad |
| Reel, TikTok or Short with no clickable caption | Code, plus a profile link | Viewers can remember a short word and type it in later | The code travels everywhere the clip is reposted or stitched |
| Long YouTube video | Both | Description links catch impulse clicks, and a spoken code catches viewers who return later | The relationship has to be disclosed inside the video as well as beside the links |
| Podcast, audio episode or live stream | Code | There is nothing for a listener to tap mid-episode | Say the code slowly, spell it once and repeat it near the end |
| Newsletter or blog post | Link | Readers are already in a browser, one click from the product | Each paid link needs labelling where the reader meets it |
| Considered purchase researched over days or weeks | Code, or a link with a long window | A short cookie window can expire before the buyer decides | Check the program's attribution window before choosing either |
| Event, shop visit or word of mouth | Code | Offline mentions leave no click behind to track | Ask whether in-store redemptions are recorded against your code at all |
| Story the brand may want to run as an ad | Code | It keeps the Story eligible for conversion into a partnership ad | The ad then uses the brand's own call-to-action link instead of yours |
Platform link rules that tilt the choice
Instagram's help centre says you can add up to 5 websites to your profile and that anyone, on or off Instagram, can see them (Add a website to your Instagram profile). Its page About link sticker on Instagram Stories adds two rules that matter for brand work: link stickers can only be used in organic Stories, and to turn a branded content Story into an ad the creator should leave the link sticker out. If a brand has asked for the right to run a Story as a partnership ad, a spoken or on-screen code is the tracking method that survives.
TikTok profile links depend on account type and eligibility, which the guide to adding a link in bio on TikTok walks through. Where a platform runs its own affiliate system, products are tagged inside the app and tracking follows that program's rules rather than your own links; the TikTok Shop commission guide and the YouTube Shopping affiliate guide cover how those work. If a brand also hands you a code for a product you tag through one of those programs, ask which of the two it will count before you promote both.
Code leaks and how to limit them
A leak happens when your code spreads beyond the audience you shared it with: posted to coupon and deal sites, passed around group chats, or picked up by browser extensions that try codes at checkout. Leaks cut both ways. You may be credited with sales you did not drive, which brands notice and dislike, or the brand may cap or cancel the code halfway through a campaign, which cuts off sales you did drive.
Links leak less, because a click has to start from somewhere, but they are not immune: a link copied into a deals forum still credits you. Neither method can tell a brand whether a buyer was persuaded by you or merely found your code. That is a reason to agree the rules on leaked redemptions before launch, not a reason to avoid codes.
- Ask for a code unique to you and to this campaign, rather than a shared brand code.
- Choose a code that reads as yours, so a redemption traced to a coupon site stands out in the report.
- Write the code's start and end dates into the agreement, along with what happens to commission after it ends.
- Ask the brand to limit the code to one use per customer and to block stacking with other offers, where its store allows.
- Agree how redemptions that trace back to coupon or deal sites are treated: full rate, reduced rate or excluded.
- Share the code only in places you control, and avoid leaving it as plain text in comment threads that are easy to copy.
- Keep a dated list of every post that shows the code, so you can update or relabel them if the campaign changes.
- Request a redemption report at agreed intervals and compare its trend with your own link taps and Story views.
- Ask the brand to warn you before it caps, changes or retires the code, so you can stop promoting it in time.
Hybrid deals: flat fee plus commission
Much of the link-or-code tension eases when a deal pays for the work and for the results separately. A hybrid structure pays a flat fee for the deliverables, which covers your production time and the exposure the brand gets regardless of sales, and adds commission on tracked sales, which shares the upside. The letters in the table are placeholders for your own figures; they show structure, not market rates.
| Structure | How it pays | Placeholder version | Suits deals where |
|---|---|---|---|
| Fee plus flat commission | A fixed fee for the agreed posts, then a set percentage of tracked net sales | Fee F for the agreed Stories and Reel, plus C% of net sales through your link or code during the campaign | The brand wants set deliverables and you want a share of the results |
| Lower fee, higher rate | A reduced fee traded for a higher commission percentage | A fee below your usual F in exchange for a rate above the brand's standard C | You have past reports showing your audience buys and want more of the upside |
| Commission with a floor | Commission only, topped up to an agreed minimum if tracked sales fall short | The greater of minimum M or C% of net sales for the period | The brand cannot fund a fee upfront but will underwrite a minimum |
| Tiered commission | A higher rate once tracked sales pass an agreed threshold | C% on net sales up to T, then C plus B% on everything above T | The brand wants to reward volume without raising its base rate |
| Fee plus milestone bonus | A fixed fee, plus a one-off bonus when redemptions reach a target | Fee F, plus bonus B once the code reaches R redemptions | Reporting is reliable and both sides trust the redemption count |
| Fee now, commission later | A fee for the campaign, with commission if the brand keeps the code live afterwards | Fee F; if the code stays active after the end date, C% of net sales from then on | Old posts are likely to keep selling after the campaign closes |
A worked example in letters: you agree fee F plus C% of net sales through your code over the campaign window. The brand's report shows gross code sales of S and returns of R. You invoice F plus C% of the difference between S and R, and the agreement already says whether redemptions traced to deal sites count. If the code sells nothing, you still invoice F, which is the point of having a fee. Brands usually want audience proof before agreeing to a fee at all, which the influencer media kit template helps you assemble.
Reporting: what to ask for before launch
Links and codes produce different evidence, so ask for both kinds of report at the start rather than after an invoice is queried.
- For links: clicks, orders, items sold and commission per link, the measures LTK's UK creator FAQ says its dashboard shows.
- For codes: redemptions, order value, refunds and the date range, exported from the brand's store rather than summarised by email.
- For both: how returns and cancellations are deducted, and when a sale counts as final.
- The attribution rule written down: whether the last click, the code or the first touch wins when they point to different people.
- When reports arrive, in what format, and how long you have to query a figure.
Keep your own log as well: the date each post went live, where the code or link appeared, and any jump you saw in profile visits or link taps. Platform analytics and a brand's order data seldom line up exactly, but when the patterns match, a disputed report is much easier to settle.
Links and codes are both ads: labels by country
A tracking method is not a disclosure. Each regulator below treats a commission link or a paid code as advertising, but they disagree on the wording that makes it clear.
| Country and guidance | Lead with | Do not rely on |
|---|---|---|
| United States: the FTC Endorsement Guides FAQ | A plain sentence such as “I get commissions for purchases made through links in this post”, or “paid link” right beside the link | “Affiliate link” or a buy-now button alone, or a personalised code with no explanation that you are paid |
| United Kingdom: CMA guidance and the ASA's affiliate advice | “Ad” at the very start of the post, Story or video | #affiliate, #aff or #sponsored, or a vague note that you “may” earn commission |
| Australia: Ad Standards and the ACCC's influencer sweep | #Ad, #PaidPromotion or a plain statement of the paid arrangement, where people will see it | A code or referral link with no explicit statement, or shorthand such as sp, spon or collab |
The FTC's FAQ adds two points that matter for codes and video. A clearly personalised discount code probably signals that you have some relationship with the brand, but not necessarily that you are paid, so the FTC recommends erring on the side of disclosure. And if your affiliate links sit under a video, the relationship should be disclosed in the video itself as well as next to the links.
UK rules also reach back in time. The ASA's affiliate advice records rulings in which posts still counted as affiliate ads after the agreed promotion period, including a TikTok post showing an expired code, and in which Stories were ads even though the code itself sat on a landing page. In Australia, the ACCC's sweep report listed promotional codes and referral links among the signs of a commercial arrangement that followers can miss without an explicit disclosure. Label once, at the start, and leave the label on the post for as long as it stays up.
Limitations of this comparison
Tracking depends on each program's terms, the shopper's browser and the brand's store settings, so the same method can behave differently from one brand to the next. The structures above are illustrations with placeholder values, not recommended rates, and nothing here predicts how many sales a link or code will produce. The disclosure summaries cover the US, UK and Australia as general information rather than legal advice; other countries set their own rules, and the ASA's influencers' guide carries a note that it will be revised to reflect the Digital Markets, Competition and Consumers Act 2024.
Record commission as business income and ask an accountant or registered tax agent how it is treated where you live. If you are choosing a program rather than a tracking method, the LTK application guide shows how one network's public terms read in practice.