EazLink guide
How do you connect a custom POS to BIR EIS?
A connector design for local POS products, receipt events, branch identity, offline queues and duplicate-safe recovery.
Updated 2026-09-06 by the EazLink team. Editorial review: EazLink Editorial Team.
Direct answer
A custom POS should send a finalized sale or invoice event through a small, versioned connector contract. The integration adds taxpayer and branch context, validates the structured invoice, manages the BIR EIS workflow and returns a status the POS can display. Keep tax credentials and retry logic out of cashier code.
What to remember
- Use a finalized source event with a stable transaction ID.
- Keep cashier actions simple and technical retries automatic or support-controlled.
- Store branch, machine and software version with each event.
- Test offline sessions, voids, returns and end-of-day procedures.
POS connector responsibilities
A narrow boundary keeps compliance code out of every screen.
| Component | Owns | Should not own |
|---|---|---|
| POS | Sale, tender, receipt and operator workflow | BIR credentials and external retry policy |
| Local adapter | Event capture and reliable handoff | Tax interpretation |
| EazLink | Mapping, validation, status and recovery | The retail accounting record |
Choose the event at the till
The connector needs to know when the sale can no longer change without a void or adjustment. Sending while the cashier is still editing creates mismatched totals.
Include the POS transaction ID, business date, branch, terminal and sequence. Those fields make later reconciliation possible.
Plan for bad networks
A local queue should survive restart and power loss. It should show age and state without allowing staff to delete difficult items.
When connectivity returns, the adapter resumes the same transaction story. It does not create a new invoice number to escape an unknown response.
Support many POS products
EazLink can use one common intake model with a small adapter for each POS. Vendors keep control of their product while the shared layer handles the Philippine workflow.
This model also creates a cleaner support boundary between cashier behavior, source data and external compliance status.
Custom POS connector checklist
- Define finalized sale, void and return events.
- Create stable branch and terminal identifiers.
- Persist a local handoff queue.
- Return a small set of visible statuses.
- Test restarts, outages and duplicate attempts.
Quick questions
Must the POS store BIR credentials?
A separate controlled component can own credentials. This reduces exposure across cashier devices.
Can the connector use a database trigger?
It may work technically, but triggers can be hard to version and support. An explicit event or outbox is usually clearer.
What if the POS has no API?
A local adapter may use an approved database, file or event integration, provided it preserves source identity and supportability.
Continue the preparation
Sources and verification
Check the current BIR rules and portal notices before making a compliance decision.