Hack'celeration Agency · Sellsy Integration 2026The Sellsy agencythat connects, migrates, syncs, automates, cleansSellsy into your whole stack, sales and cash in sync.
Sellsy puts CRM and invoicing in one tool, then quietly drifts from the rest: payments matched by hand, accounting re-keyed at month-end, your e-commerce living in a parallel world. We wire Sellsy into your accounting, payment, e-commerce and CRM so the whole quote-to-cash cycle runs on its own.
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GeminiA Sellsy integration agency actually connects your tools.
Plenty of people can set up Sellsy. Wiring it cleanly into the rest of your stack so data moves without a human in the loop is a different job. Here are the four things we own.
- Implementation
CRM and the quote-to-cash cycle, set up around you
Sellsy is CRM and invoicing in one tool, and that's exactly why a half-baked setup hurts twice. We configure your pipelines, custom fields, quote and invoice templates, and the quote → invoice → dunning cycle around how you actually sell and bill. Your team opens Sellsy and the sales-to-cash flow just works.
See a typical setup - Integration
Sellsy wired into the rest of your stack
This is the core of the integrator job. We connect Sellsy to your accounting (Pennylane), payment (Stripe, GoCardless), e-commerce, and the CRMs and tools your team uses. Through the Sellsy API, webhooks, or n8n and Make when the flow gets complex. Quotes, invoices and payments move on their own instead of being re-keyed between Sellsy and everything else.
See the integrations - Migration
Data migration with nothing lost
Coming from HubSpot, Pipedrive, a spreadsheet or a separate invoicing tool? We map the records, dedupe, keep your client, quote and invoice history intact, and switch over without breaking your live automations. Every migration runs on a test account before it touches your production Sellsy.
See the migration method - Automation & AI
Billing that chases itself, not your team
Once Sellsy is connected, we automate it. Quote-to-invoice automation, payment reconciliation, dunning sequences, AI-driven enrichment, reporting that fills itself in. We're an automation and AI agency first, so we go past Sellsy's native automations into n8n, Make and AI when the use case earns it.
See AI on Sellsy
We wire Sellsy like a system, not a gadget.
An integration is data plumbing, and on the billing side a leak costs cash. Botch it and you find out at month-end, when a payment doesn't reconcile and a client gets chased for an invoice they already paid. So we treat every flow with the same rigor, whether it links Sellsy to Stripe, Pennylane or a data warehouse.
- Audit · map your current stack and the data flows to wire into Sellsy
- Mapping · define which Sellsy objects talk to which systems, and which way
- Build · wire each integration via the Sellsy API, webhooks, n8n or Make
- QA · test every flow on a test account before switching production over
An automation agency, not a seat reseller.
We don't sell a Sellsy partner tier. We come from automation and AI, so we see Sellsy for what it is: the sales-and-cash hub of your stack that has to talk to everything else. That's exactly what's missing when a setup ends at the invoice template with no integrations.
- We come from automation and AI, not from reselling seats. Sellsy is a node in your stack, not the whole point.
- We build integrations that hold: error handling, retries, logs, alerts when a sync breaks.
- We teach your team to maintain the automations, we don't lock you into a retainer to change a template.
- No badge to sell: we're judged on the flows running in your account, not on a partner tier.
Sellsy at the center, your tools all around it.
We stay tool-agnostic. If your system exposes a documented API and webhooks, we connect it to Sellsy. Here are the tool families we wire most often.
- Integration
Accounting
Pennylane, QuickBooks and your accountant's tool: invoices and payments flow to accounting, no double entry at month-end.
- Integration
Payment & banking
Stripe, GoCardless, bank feeds: payments reconcile against Sellsy invoices, dunning fires on its own, zero manual matching.
- Integration
CRM & sales
HubSpot, Pipedrive, Salesforce: a won deal in your CRM creates the quote in Sellsy, status flows back to the rep.
- Integration
E-commerce
Shopify, WooCommerce, PrestaShop: orders create the client and invoice in Sellsy to trigger the right follow-up.
- Integration
Data & reporting
BigQuery, Snowflake, Looker, Power BI: we push Sellsy data into your warehouse for dashboards that cross sales and cash.
- Integration
No-code orchestration
n8n, Make, Zapier: when a flow touches four or more tools, we orchestrate it cleanly instead of stacking fragile native automations.
We map your stack, you leave with an integration plan.
Before quoting anything, we take 60 minutes to list your tools and the flows to wire into Sellsy. You leave with a map of your stack, the priority integrations and an honest take on what's worth automating first. Zero pitch, just an integrator's read on what's blocking your data.
- A map of every system that holds your client and billing data
- Priority flows to wire into Sellsy, in order
- Method per flow: native API, n8n, Make or a connector
- A frank take on the integrations that aren't worth the cost
How we run a Sellsy integration.
Five steps, in order, no skipping. We don't build before the mapping is signed off, we don't cut over your account without QA, and we hand your team the keys at the end. Each step has a deliverable and you sign off before we move on.
- Step 1 · Stack audit
Map your stack before touching Sellsy
We sit down with the teams that live in the tools, sales, finance, ops, and list every system that holds client and billing data: your current CRM, your invoicing or accounting tool, payment, e-commerce, spreadsheets. We note where data duplicates, where it leaks, and which billing tasks are still done by hand. You leave with a clear map of what needs to talk to Sellsy and in what order we wire it.
- Step 2 · Data mapping
Define the data model before the first integration
Before opening an editor, we write the mapping: which Sellsy objects (contacts, companies, opportunities, quotes, invoices) match which records in your other systems, which fields sync, which direction, and which side wins on conflict. We document dedupe rules and the statuses that trigger an action. An operator on your side signs off before we build.
- Step 3 · Building integrations
Wire each flow with the right tool for the job
We pick the most robust path for each flow. The Sellsy API and webhooks when the exchange is simple and two-way. n8n or Make when a flow chains several services, needs parsing or conditional logic your team will extend without us. A maintained connector when one exists and holds up. Every integration ships with its error handling and logs from day one, not bolted on later.
- Step 4 · Test-account QA
Test every flow before switching production
We never wire an integration straight into your live Sellsy. We replay flows on a test account with representative data: a new quote, a Stripe payment, a Shopify order, a CRM deal. We check the data lands on the right object, in the right format, with no duplicates, and that existing automations don't break. You sign off on each scenario before the switch.
- Step 5 · Monitoring & handoff
Watch the flows and make you self-sufficient
An integration that breaks silently is worse than no integration, and on the billing side it costs cash. We set up alerts when a flow fails, a sync-health dashboard, and a retry path for transient errors. Then we train your team: they can read the logs, re-run a flow and tweak a simple automation. The goal is that you don't need us to breathe.
We're judged on the flows that run.
No partner badge to display, so we lead with what actually matters: feedback from the sales and finance teams using the integrations we wired, day in and day out. Our Trustpilot reviews come from those operators, not from marketing.
- Every integration ships with its logs and failure alerts
- Knowledge transfer so your team stays self-sufficient
- A broken sync shows up right away, not at month-end close
- Trustpilot reviews come from the teams living in Sellsy
The questions we get asked on repeat.
What does a Sellsy integration agency actually do?
A Sellsy integration agency wires Sellsy into the rest of your tools so data moves on its own. The difference from a setup-only shop: we don't stop at CRM and invoice templates. We connect Sellsy to your accounting, payment, e-commerce and the CRMs your team uses, through the Sellsy API, webhooks or platforms like n8n and Make. The point is to kill double entry across the quote-to-cash cycle.Are you a certified Sellsy partner?
No, and we'd rather be upfront. We don't lead with a Sellsy partner badge. What we have is hands-on integration experience: we're an automation and AI agency, so connecting Sellsy to an existing stack via its API and webhooks is our daily job. You judge us on the flows running in your account, not on a partner tier. If you only need the licenses, you buy those from Sellsy directly.How much does a Sellsy integration cost?
It depends entirely on scope: how many systems to connect, which way the syncs run, how much data to migrate and how complex the billing rules are. Wiring Stripe and Pennylane into Sellsy is nothing like syncing a separate CRM and a data warehouse both ways. We don't throw out a flat package. We start with a free 60-minute audit to frame the need, then quote a fixed scope. No vague hourly billing.Which tools do you connect Sellsy to?
We stay tool-agnostic. Accounting: Pennylane, QuickBooks. Payment and banking: Stripe, GoCardless, bank feeds. CRM: HubSpot, Pipedrive, Salesforce. E-commerce: Shopify, WooCommerce, PrestaShop. Data: BigQuery, Snowflake, Looker, Power BI. And for complex flows we orchestrate through n8n, Make or Zapier. If your tool exposes a documented API and webhooks, we can wire it into Sellsy.Can you migrate from another CRM or invoicing tool to Sellsy?
Yes. We map the records (contacts, companies, opportunities, quotes, invoices) to Sellsy, dedupe along the way, keep your client and billing history intact, and replay the migration on a test account to confirm the numbers tie out before touching production. Billing migrations are unforgiving, so the rule is firm: no cutover without a QA pass and a finance sign-off on your side.Sellsy or HubSpot: which should we wire up?
Different jobs. Sellsy bundles CRM, invoicing, pre-accounting and treasury in one tool, strong for French SMBs that want sales and billing in one place. HubSpot is broader on marketing and content but bills separately. If your pain is the quote-to-cash cycle and you want billing native to the CRM, Sellsy fits. If it's marketing automation at scale, look at HubSpot. We integrate both honestly, see our HubSpot integrator page, and we'll tell you which fits during the audit.How long does it take to wire Sellsy into our stack?
For a scoped integration (2 to 3 systems connected to Sellsy), count 3 to 6 weeks: audit and mapping in week 1, building flows in weeks 2 to 4, test-account QA and cutover after that. A migration from a separate CRM and invoicing tool with large volume can run longer. We always split into batches to ship a first useful flow fast, rather than waiting for everything to be perfect before wiring anything.Is integrating Sellsy via n8n or Make better than a native connector?
It depends on the flow. If a maintained connector covers your need, we use it, it's simpler to maintain. We go through n8n or Make when the flow chains several tools, needs conditional logic, data parsing or transforms the connector can't handle. The upside of n8n and Make: you can see the flow, change it, and you're not boxed in by a black-box connector's limits.How do you handle GDPR on Sellsy data?
We configure Sellsy on the right footing: consent tracking, lawful basis, retention windows, and the right to erasure wired into your automations. For integrations, we make sure data travels over secure connections and that the third-party tools you use support EU hosting when it's required. Sellsy itself is French and EU-hosted, which helps. If you have a DPO, we work with them on the records of processing.
Stop re-keying invoices. Connect Sellsy.
A 60-minute audit, your stack mapped, a prioritized integration plan. If your team can wire the flows in-house, we'll tell you and hand you the plan. If we're the right fit, we handle it.