Share the dataset, not the login: Meta's partner model

To share a Facebook pixel with an agency, the client adds the agency's business portfolio as a partner on the pixel's dataset, using the agency's business portfolio ID. The agency accepts, then assigns the dataset to its own people and ad accounts. Nobody's password changes hands, the client stays the owner, and ending the work later means removing one partner.

A pixel is a dataset now

The pixel did not go away; Meta renamed what it lives in. A dataset is the container in Events Manager that holds a business's website events, whether they arrive from the pixel code in the browser or from the Conversions API on the server. It keeps the pixel's ID, so nothing on the website needs to change, and older guides that say "pixel" are describing the same object.

Like a Page or an ad account, a dataset belongs to exactly one business portfolio, the one it was created in. Other portfolios can be given access to it. Access is not ownership, and that difference decides what happens to a client's conversion history when an agency relationship ends.

How to share a Facebook pixel with an agency, step by step

Meta moves its menus around and renames them, so take these as the route rather than the exact labels.

1. The agency sends the client its business portfolio ID. It is on the business info page in the agency portfolio's settings, and it is a number, not anybody's email.
2. The client opens its own business portfolio's settings, goes to data sources, and opens the dataset.
3. The client chooses to assign a partner, enters the agency's portfolio ID, and picks what the agency may do with the dataset: use it for ads, see its performance, or manage it.
4. The agency accepts the share in its own portfolio.
5. The agency assigns the dataset to the people who need it, and connects it to the ad accounts that will optimise against it.

The ad accounts follow the same model. A client shares its ad account with the agency's portfolio as a partner, and the agency hands that access to its staff. A partner can pass on what it was given or less, never more, so a missing permission on the agency side usually means the asset reached the agency's portfolio and was never assigned to the person. How people and partners differ as two ways into a portfolio is set out in business portfolio vs Business Manager.

How it works: Logins and 2FA codes

The client creates it; the agency is added

The common mistake happens before any sharing: the agency creates the pixel, inside the agency's portfolio, because that is where its people already are. It works on day one. On the last day, the dataset and every event it collected belong to the agency, and the client either negotiates for it or starts again with an empty one. A dataset made by the client and shared to the agency never has that conversation. The same rule, applied to a client's Facebook Page, is in who owns the Facebook Page, agency or client.

Why a shared login is the wrong tool

Partner access exists so that nobody has to hand over a Facebook login, and handing one over goes wrong in a predictable order.

A personal Facebook account belongs to one person, and Facebook's terms have long asked people not to share their password or let others into their account. A client who gives an agency their own login is breaking that before anything else happens.

Then the sign-in itself looks like a takeover. The account that has always signed in from the client's phone in one city suddenly signs in from an agency laptop somewhere else. Meta's security systems are built to notice exactly that, and the usual answer is a checkpoint: a code sent to the client's phone, or an identity check, at the moment the agency is trying to launch a campaign. If two-factor authentication is on, every sign-in needs the client; if somebody turned it off to make sharing easier, the account is now weaker for everyone.

And there is nothing to revoke. When a person who knew the password leaves the agency, the only way to take their access away is to change the password and send the new one to everybody else. Removing a partner is one action on the client's side, and the agency removing a person is one action on its own. The spreadsheet version of this problem, and what replaces it for logins that have no partner model, is in the shared password spreadsheet.

Where a browser profile fits

None of this needs an anti-detect browser, and we would not suggest one for it. The agency's people sign in to Meta with their own Facebook accounts and reach the client's dataset and ad accounts through partner access. In Mosaic that means one person's Facebook sign-in sits in one profile of its own, with its own cookies and its two-factor setup key in that profile's vault.

The profiles per client are for what Meta's partner model does not cover: the client's Shopify admin where the pixel was installed, their analytics, the tag manager. Mosaic keeps accounts you are entitled to run apart; it does not change what a platform allows. Verification is the one place the client's legal details and the portfolio meet, covered in what Meta business verification ties together.