The fourth guest on your monday account costs money. If you work with a dozen clients who each need to say yes to something occasionally, that adds up to seats bought so people can click a button.
What it costs
Worth knowing before you design a process around guests.
Check your own plan — the allowance differs — but the shape is the same everywhere: a small number of guests are free and after that each one is a member.
The distinction that matters
Almost every wrong answer here comes from treating them as the same thing.
A designer working in your boards for six weeks is collaborating. They need to see context, move items, upload things, read the comments. Make them a guest on a shareable board. That is exactly what shareable boards are for and nothing else will do the job as well.
A client who needs to say yes to one proof, twice a quarter, is deciding. They do not need context, or a board, or a login. They need to see one thing and answer one question. Buying them a seat is the least of it — the real cost is that creating an account is more friction than the decision is worth, so they put it off, and your approval sits unanswered for a week.
That second case is where portals get suggested, and a portal is a place somebody has to go, with credentials they have to keep. For a twice-a-quarter decision it is the same problem in a nicer wrapper.
What to do instead
Three ways, in increasing order of how much you will trust the answer later.
Email, and record it by hand. Free, works today, and the record is a mail thread somebody has to go and find. Fine for low stakes; poor when a revision is disputed, because “I never saw that version” is exactly the argument a mail thread cannot settle.
A monday form. Genuinely useful for collecting a response from somebody with no account, and it will not show them the document they are agreeing to, or tie their answer to a specific version of it.
A signed link that decides one approval. The person opens it, sees what they are approving, and answers. No account, no seat, no portal to join. The link names one person, expires, and is useless for anything else.
Questions
It depends entirely on what the link is. A link that grants access to a board is a credential and should worry you. A link that authorises one decision on one approval, by one named person, and expires, is not much more dangerous than the email it arrives in — it cannot read your boards, list your other approvals, or be reused once the decision is made.
Then the colleague can see that one approval. Whether that matters is a judgement about the document, not about the mechanism — and it is worth designing for, which is why a good link expires and records who it was addressed to even when somebody else uses it.
You should be able to. The point of doing this properly is that the outside decision lands in the same place as the internal ones — same trail, same item, marked as having come from outside rather than presented as a monday session that did not happen.
What we built
The first two need nothing from us, and this page has told you when they are enough.
An approver outside your company gets a signed link. They see the request and the documents previewed, and they approve, ask for a change, or decline. No monday seat, no login, no per-approver cost — the price is per account, so adding the person whose signature you actually need never costs more.
Their decision lands in the same trail as everybody else’s, marked as having come from outside, against the exact file versions that were on their screen.
Three approvals a month, free, every feature turned on — including the external approver.