Find agency partners you would trust with a client.

1. Define the missing capability and the relationship

Describe the client problem, the outcome, the required expertise and the constraints. A branding studio might need an ecommerce development team that can translate a design system into an accessible storefront while coordinating with the client's internal operations lead.

Then choose the relationship you are actually looking for. In a referral, you introduce a specialist and the client agrees the work directly with that team. In an open collaboration, both agencies have visible, defined roles on a shared initiative. In either case, make ownership understandable to the client.

Specify practical requirements: timezone overlap, platform experience, typical scope, accessibility needs, communication expectations and who can implement decisions. Separate genuine requirements from preferences. You may need two hours of shared working time, not an office in the same city.

2. Search for the capability, then inspect the work

Start in Browse Agencies with the missing service. Narrow by industry or platform where it matters. A Shopify agency search may be a useful entry point for the storefront example, followed by checking relevant credentials and projects on each profile.

Follow case studies and original sources. Ask whether the work resembles your project's constraints: integrations, internal team size, migration complexity or an established design system. The most famous client logo may tell you less than a modest project with a clearly described delivery process.

You can also search relevant client names in Brands to discover more agencies. Treat those connections as agency-reported. Two agencies naming the same brand does not show that they collaborated, and a platform credential does not establish that they will be a good partner.

3. Build a shortlist around evidence and unknowns

For each candidate, write down the work that makes it plausible, the source URL and the questions you cannot answer publicly. Start with three. If all three have the same unresolved critical requirement, investigate that requirement before collecting more names.

• Capability: relevant scope with a clear explanation of the agency's role.
• Client fit: experience with comparable complexity and operating constraints.
• Collaboration: any published explanation of discovery, handoffs, approval and delivery.
• Practical fit: public location, platforms and engagement information.
• Unknowns: current capacity, assigned people, communication habits and commercial fit.

Do not quietly turn unknowns into positive scores. A beautiful case study cannot tell you whether the team that made it still works there or has space next month.

Worked example: a branding studio needs a development partner

Illustrative example: the names and findings are fictional, not actual directory records.

Your branding studio has a client planning a Shopify storefront refresh. You want to own the brand and design system. The partner needs to own technical discovery, implementation and launch planning, with both agencies visible to the client.

You find Cedar Build, which publishes a relevant migration case; Signal Cart, which describes ongoing ecommerce optimization; and Atlas Commerce, which shows complex integrations. All three could be worth investigating, but the evidence points to different strengths.

Your client's immediate risk is integrating a revised storefront with the existing fulfillment setup. You prioritize the candidate with a clearly described integration example for the first call, while keeping the others in reserve. You do not assume it is best overall or available.

On that call, you ask who would own technical discovery, what must be tested before launch and how design decisions would be reviewed. If the answers fit, propose a paid discovery engagement that produces an integration map, dependencies and acceptance criteria. That is a useful deliverable even if you decide against a larger collaboration.

4. Ask questions that reveal how the work will happen

A first conversation should establish more than enthusiasm and a shared dislike of bad clients. Use a realistic scenario and ask how the team would handle it.

1. “Walk us through a comparable project. What did your team own, and what did the other teams own?”
2. “Who would do this work now, and what capacity do they have?”
3. “What do you need from us and the client before you can give a reliable scope?”
4. “How do you handle a request that changes cost or timing after work begins?”
5. “When a deadline is at risk, who tells the client, and how early?”
6. “How would design, technical and commercial disagreements get resolved?”
7. “Can you describe a collaboration that was difficult and what you changed afterward?”
8. “What kind of project should we avoid sending you?”

Listen for named responsibilities, explicit dependencies and examples. Ask for a relevant reference when appropriate and with the referee's permission. Respect confidential material; explaining a working method should not require exposing another client's private data.

5. Agree how the client relationship works

Before making a consequential introduction or proposing joint delivery, document the operating decisions. This is a working checklist, not a substitute for an appropriate agreement.

• Who contracts with and invoices the client, and who approves changes?
• Who owns each deliverable, the overall timeline and client communication?
• How will both teams explain their roles to the client?
• What access is required, who grants it and how is it removed when work ends?
• How are feedback, defects, support and escalation handled?
• Are there referral fees or other commercial interests, and how will they be disclosed?
• How are future opportunities involving the shared client discussed?
• What happens if either agency needs to stop or replace assigned people?

Resolve disagreements while the relationship is still hypothetical. “We assumed you were managing that” becomes much more expensive after the client has heard a launch date.

6. Start with a small paid engagement

Choose a bounded piece of real work with a useful standalone output: technical discovery, a measurement plan, an integration specification or a limited implementation. Define the scope, owner, dependencies, cost, timeline and acceptance criteria before beginning.

Evaluate how the team asks questions, identifies risks, meets commitments, handles feedback and communicates changes. Review the final output against the agreed criteria. Good chemistry is helpful; a dependable working process is what you need to observe.

At the end, decide whether to proceed, adjust the relationship or stop. For referral-only relationships where a joint engagement would be artificial, use relevant references and a clear introduction process instead. Avoid turning qualification into a demand for unpaid strategy.

Make the relationship easy to use

Keep a short partner note: the situations to send, the situations to avoid, the best contact, last confirmed capacity and what you have actually observed together. Reconfirm availability before promising a client an introduction will solve a timing problem.

After an engagement or referral, ask both sides what worked and what created friction. Update the note. A small set of partners with known strengths and boundaries is more useful than a large list of agencies you once met.

Use competitive research to distinguish an alternative from a complement, or the prospecting guide when you need to understand the buyers both teams could serve.