Withholding tax is where ERPNext's native tax handling runs out of road for finance teams that operate under TDS (India) or WHT regimes. ERPNext core ships a basic Tax Withholding Category, but real compliance demands more: per-category thresholds evaluated against cumulative supplier billing across a fiscal year, lower/nil-deduction certificate handling, PAN/TIN-driven higher rates, section-wise mapping, and the ability to produce deduction certificates and return-ready extracts. Teams end up patching this with spreadsheets, manual journal entries and quarter-end reconciliation marathons — exactly the error-prone, audit-risky work that should be automated inside ERPNext.

ECOSIRE builds a proper Frappe app (its own module, not a fragile pile of customizations) that layers a full withholding engine onto ERPNext. We model withholding categories, rates and thresholds as dedicated DocTypes, then hook into the Purchase Invoice, Sales Invoice, Payment Entry and Journal Entry lifecycle via hooks.py doc events (before_save, on_submit, on_cancel). Server-side logic computes the correct withholding amount, checks whether a supplier or customer has crossed the single-transaction or cumulative-invoice threshold for the relevant category, applies the higher no-PAN/no-TIN rate where required, and writes the deduction lines back onto the document. Because the calculation lives in server scripts and whitelisted methods rather than the browser, the numbers are consistent whether a document is created in the UI, imported, or posted through the Frappe REST API.

On top of the engine we build the compliance outputs your accountants actually file. A Withholding Certificate DocType generates numbered, print-format-ready certificates (Form 16A-style for TDS, or your jurisdiction's equivalent) with a controlled naming series and role-gated issuance. Scheduler events (scheduler_events in hooks.py) can run periodic jobs to accrue liabilities, flag suppliers approaching thresholds, and stage return data. Statutory return extracts — for example 26Q/27Q for Indian TDS or the PND series for other WHT regimes — are produced as query reports and downloadable files mapped to the exact columns your filing utility expects. Permissions and role profiles (a Withholding Manager vs. a read-only reviewer, for instance) keep issuance and rate configuration separate from data entry.

Because this is build-to-order, nothing ships until we agree on your exact regime. It starts with a scoping call where we capture your jurisdiction(s), the specific sections/categories and rates, threshold rules, certificate formats and the return formats you file. We then build against Frappe/ERPNext v15/v16, deliver on a staging site for UAT, and only cut over to production once you sign off. Typical delivery is 2-4 weeks from confirmed scope depending on how many regimes and return formats are in play. You receive the installable source, a git repository handover and documentation, so the app is yours to run — with an agreed post-go-live support window from ECOSIRE.