A sub ID is a label you stick on your own link so the reports tell you where each click came from. One offer link can carry "facebook", "campaign 12" and "video 3", and the network will split clicks and conversions by those labels for you.
Sub IDs are free-text parameters an affiliate appends to a network tracking link to segment their own traffic. The network stores them with each click and returns them in reports and, if asked, in postbacks. Platforms name them differently: Scaleo uses sub_id1 to sub_id5, HasOffers-style platforms aff_sub to aff_sub5, others sub1 to sub7 or s1 to s5. Whatever the name, the network does not interpret the values; they exist so the affiliate can read results by dimensions the network knows nothing about.
A sub ID is not a click ID. The click ID is unique for every click and serves to match one conversion to one visit; a sub ID repeats across thousands of clicks and groups them. Typical dimensions are traffic source, campaign or ad set, placement, creative and landing variant. Some affiliates also use a sub ID to carry their tracker’s click ID, but where the platform offers a dedicated click-ID parameter, that is the better place for it.
Sub IDs matter most to affiliates who do not run their own tracker, because they are then the only way to see which placement or creative converts. They matter to the network too: when an advertiser flags poor quality, a clean breakdown by source lets the affiliate cut the weak segment instead of losing the whole offer. Some advertisers require a source sub ID on every click for exactly this reason.
Practical limits apply. Values can be truncated, special characters encoded or stripped, and some platforms hash or hide sub IDs before passing them to advertisers. A stable convention, lowercase, no spaces and the same position always meaning the same dimension, keeps reports comparable months later and lets you merge network data with your own spreadsheets.
An affiliate promotes a VPN offer on two native sources and one email list, using sub_id1 for the source, sub_id2 for the campaign and sub_id3 for the creative.
| sub_id1 | sub_id2 | sub_id3 | Clicks | Conversions | CR |
|---|---|---|---|---|---|
| native-a | vpn-us-01 | img-03 | 8,200 | 98 | 1.2% |
| native-a | vpn-us-01 | img-07 | 7,900 | 47 | 0.6% |
| native-b | vpn-us-02 | img-03 | 6,100 | 18 | 0.3% |
| nl-0915 | text-01 | 1,400 | 39 | 2.8% |
Overall the offer converts at 0.9% (202 of 23,600 clicks), which looks unremarkable. The labels show that creative img-03 on source A and the email list carry the result, while source B converts at about a third of the average and is the first segment to cut if the advertiser raises quality concerns. Numbers are illustrative.
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A parameter you add to your affiliate link to label traffic, for example by source, campaign or creative, so the network reports clicks and conversions per label.
It depends on the platform. Five is common (Scaleo sub_id1 to sub_id5, aff_sub to aff_sub5 on HasOffers-style platforms); some allow more. The network’s link builder shows the available fields.
No. A click ID is unique per click and matches one conversion to one visit; a sub ID is a label shared by many clicks.
Sometimes. Networks may pass them on, hash them or hide them, so treat them as visible and never put personal data in them.
References are listed as plain text on purpose; look them up by title and publisher. Updated: 2026-10-09.
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