Connection invites, limits, and what errors mean
LinkedIn invite limits, common provider errors, and how Fulreach classifies them.
Last updated: May 2026
Why invites fail or pause
LinkedIn connection outreach is tightly rate-limited. Fulreach maps Unipile / LinkedIn responses into stable categories so you know whether to wait, change targeting, or reconnect.
Typical HTTP patterns (simplified)
| Pattern | Often means |
|---|---|
| 422 with invite-specific subtypes | Usually not “random server error”—often already connected, already invited, cannot invite attendee type, or cannot resend yet (limit or cooldown) |
| 429 | Short-term API throttling—Fulreach may auto-retry with backoff |
| 5xx | Provider issues—retries may apply |
| 400 | Validation (e.g. missing email when required) |
Because 422 covers multiple semantically different cases, Fulreach inspects body details to decide if a failure is permanent (never retry this prospect) vs account limit (pause/wait).
Error buckets (user mental model)
- Needs attention — auth expired (reconnect), weekly/daily ceilings hit, checkpoints, outages.
- Auto retry — temporary transport / rate limits Fulreach replays responsibly.
- Permanent failure — already connected / cannot invite attendee / deliberate duplicate suppression.
UI surfaces provider codes with helpful prefixes distinguishing upstream (UNI:) versus Fulreach internal classification (APP:) for faster support triage referencing internal dashboards.
Keep provider HTTP codes + subtype strings intact when escalating—Fulreach persists them verbatim for reproducibility without hunting raw payloads.
LinkedIn context (informative ranges)
Rough public guidance echoed in integrations literature (Paid vs Free LinkedIn)—actual ceilings vary by account warming & LinkedIn classification:
- Paid-like accounts historically ~ 80–100 invites/day neighbourhood with weekly caps differing.
- Free accounts materially lower—Fulreach slows or stops rather than brute forcing thresholds.
Fulreach honours duplicate prevention (recent invite windows) outlined in Scheduling article.