What these schemes are
A certification or membership body publishes a public register of the companies that carry its mark. Getting into that register is usually free, and the register is often an old domain with real authority. That makes it look like an easy directory listing.
The condition is that their badge, and the link that comes with it, has to be visible on your own website. Take the badge down and the listing usually goes with it. It is a trade rather than a submission.
What the trade is actually worth
A reciprocal link is weaker than a one-way link, and both search engines and language models can see the pattern. Two sites pointing at each other say less about either of them than one site pointing at the other unprompted.
That does not make it worthless. What makes these listings worth having is the part that has nothing to do with links: a certification register is a page a buyer checks before they trust you. The link is a side effect of a claim you can actually back up.
When to take the trade and when to walk
The test is whether you would want the certification if the link did not exist.
- Take it. when the scheme matches something your business genuinely does, and the badge is one you would put in your footer anyway.
- Walk away. when the certification is bought rather than assessed. A mark anyone can pay for tells a reader nothing, and the register it puts you in is a link farm with better manners.
- Check the direction. before you start. Some registers link out without asking for anything back, and those are simply good listings.
How to spot the gate before you start
The requirement is rarely on the sign-up page. It usually appears in the terms, or in a step near the end after you have filled in a form. That is why an afternoon disappears.
Every entry of this kind in our catalogue carries the requirement in the guide, at the top, before the first step. If a scheme needs a link back from you, you know it before you open the form rather than after.
What we have catalogued in this category
Of the 493 places in the catalogue, 23 are of this type.100% of those pass a following link, and 100% are ones a beginner can complete without prior accounts or a verified business.
| Market | Platforms |
|---|---|
| 🇩🇰 DK | 23 |
Counts describe our catalogue rather than the web as a whole. We publish the numbers, not the list: the list is the product.
One of these is on the free tier
No payment and no card. These are the ones you can open and work through today, and they are a fair sample of how the rest are written up.
| Platform | Market | Link | Difficulty | Time |
|---|---|---|---|---|
| Viergroenne.dk | 🇩🇰 DK | dofollow | Easy | 30-45 min |
What sits behind this
This category is one of 22. The whole catalogue holds 493 places across 5 markets, and every one of them is written up step by step in both English and Danish.
The work behind the list
- 129 of them have been opened and checked against the page that is actually there now, not just imported from a list.
- 130 of them have a link straight to the form, so you are not hunting for it on their front page.
- Authority figures from Ahrefs are refreshed on the first of every month. Last run 1 September 2026.
What we warn you about
A list you scraped yourself will not tell you what does not work. This one does, and that is usually where the hours go.
- 24 of them only count your submission once you have put a link back to them on your own site. That is in the guide before you start.
- 7 of them turned out not to be directories at all. They are flagged rather than deleted, because they can still be an opportunity.
- 5 of them have stopped responding. They carry a warning rather than wasting your time.
- 68 of them pass nofollow. We say so, including when the directory itself claims otherwise.
20 of the 493 can be opened and worked through without paying anything. They are not a selection of the weak ones.
Examples of this kind of platform
Names most practitioners would recognise, to make the category concrete: B Corp, Ecovadis, Green Key, Svanemaerket, ISO certification registries.
Common questions
Do reciprocal links hurt your site?
A handful of them from schemes you genuinely belong to will not. A profile built mainly on link exchanges will, because the pattern is easy to detect and says nothing about whether anyone values your site.
Should I use nofollow on the badge I display?
No. If the certification is real, the link is honest. Marking it nofollow while taking the listing is the worst of both.
Are paid certifications worth it for links alone?
No. If the only reason to buy the mark is the register entry, the money is better spent elsewhere. The register is only valuable because readers believe the assessment behind it.