Definition
Co-sell is when a vendor's sales team and a partner's sales team work the same deal together. They share account details, split tasks and agree on who does what with the customer. Co-selling is common with resellers, service providers, technology alliances and cloud providers.
Good co-selling needs clear roles. One side may own the relationship while the other brings technical depth or pricing. Both sides need to know how credit and compensation will work.
Co-sell only works when field teams trust each other. Regular account mapping and quick handoffs help build that trust. Rules of engagement set the ground rules.
In practice
A vendor's account executive and a partner's solutions architect run a joint discovery call, then the partner builds the services quote while the vendor handles product pricing.