Not our data?
That's fine — bring your own.
You've already paid for data elsewhere. Upload your contacts via CSV or REST API and run them through the full Happierleads stack — Email Waterfall, Follow-up Engine, Inbox Engine. Your data, our infrastructure.
Importing your own data is free. You only pay for the infrastructure you use.
More coverage. More control. Zero lock-in.
Not every company wants to rely on a single data vendor. If you buy from ZoomInfo, Apollo, or anyone else — or run your own prospecting — don't let those contacts sit in a spreadsheet.
CSV upload in seconds
Drop any CSV with an email column and we auto-map the fields. No schemas, no formatting work — just drag, drop, and go.
REST API for automations
Push contacts from your CRM, data warehouse, or enrichment pipeline. Supports single records and batches of up to 10,000 per call.
Mix with identified visitors
Layer your imported lists on top of Happierleads-identified site visitors. One unified dashboard — no juggling between tools or tabs.
Upload once. Available everywhere instantly.
Whether the list came from ZoomInfo, a trade show badge scan, or your own research — drop it in as a CSV or push it via API and it's immediately available inside every Happierleads tool.
- check_circleDrag-and-drop CSV. Auto-detect for first name, last name, email, company, job title, and any custom columns you include.
- check_circleREST API. POST contacts from any system — CRM, data warehouse, enrichment pipeline. No ETL middleware required.
- check_circleDe-duplication built in. We match against existing contacts automatically — no messy overlap with your identified visitors.
- check_circleInstant enrichment. Every imported contact is run through the Email Waterfall to validate addresses and fill any gaps before outreach starts.
Your data. Our infrastructure. All of it.
Once your list is in, it works exactly like a visitor-identified lead. Verify addresses, enrol in sequences, send from warmed mailboxes — same features, same quality, your data.
- check_circleEmail Waterfall. Verify every imported address through 8+ providers before sending — so stale data from any vendor never damages your sender reputation.
- check_circleFollow-up Engine. Enrol imported lists in AI-personalised multi-step sequences — same spin tags, same conditional branching as your identified visitors.
- check_circleInbox Engine. Send from managed mailboxes with Heat Score™ monitoring. Your list, our deliverability infrastructure.
- check_circleICP scoring. Upload company data alongside contacts and we score the list against your ICP — highest-fit records rise to the top automatically.
Start with your own list today
Sign up, go to Lists, and drop your CSV. Your contacts will be verified and ready to sequence in minutes.
Built for teams with existing data
Multi-provider shops
You buy from ZoomInfo, Apollo, and Lusha. Don't run each through separate tools — consolidate all of it into one sending infrastructure.
Event & conference leads
Scanned 600 badges at a trade show. Upload the CSV on Monday and have personalised follow-ups running by Tuesday.
RevOps & API teams
Build enrichment pipelines that push ICP-qualified contacts directly into Happierleads via REST API — no manual exports, no spreadsheet chaos.
FAQ
Is importing my own data free?
Yes — importing contacts via CSV or API is free. You only pay when you use the sending infrastructure (Inbox Engine, Email Waterfall). If you're on a plan, your imported lists use the same allowances as your identified visitors.
What format does the CSV need to be in?
Any CSV with at least an email column. We auto-detect common column names (first_name, last_name, company, title, phone) and let you manually map anything non-standard during the import flow.
What does the REST API support?
POST single contacts or batches of up to 10,000 per call. Supports upsert so re-sending the same contact just updates the existing record. Full API docs are available inside your dashboard once you're signed in.
Can I mix my imported contacts with Happierleads-identified visitors?
Absolutely. All contacts — identified, imported, or API-pushed — live in the same dashboard, share the same ICP scoring, and flow through the same sequences. There's no forced separation.
Are there limits on how many contacts I can import?
Individual CSV uploads support up to 100,000 rows. There's no cap on total contacts stored. API imports are rate-limited by plan — contact us if you need higher throughput.
More Happierleads features
Email Waterfall
Chain 8+ providers to get a verified email for every contact — imported or identified.
Follow-up Engine
Multi-step AI-personalised sequences that stop automatically when someone replies.
Inbox Engine
Managed mailboxes and warmed domains — Heat Score™ routing for 98% primary inbox delivery.
