Tally TDL Addons & Customisation

TDL — Tally Definition Language — is the native scripting and programming framework built into every copy of TallyPrime and Tally ERP 9. Unlike third-party plugins that sit outside Tally, TDL is compiled and executed entirely within the Tally engine itself, giving it deep access to every data object, voucher, ledger, report, and function inside the software. TDL can define new fields, new voucher types, new report formats, new menu items, new validation rules, automated workflows, and even complete sub-applications — all of which behave as though they are native Tally features. This tight integration means TDL customisations are faster, more stable, and more reliable than external integrations built using ODBC or file-based data extraction. A TDL Addon compiled into a TCP (Tally Compiled Program) file loads in milliseconds at Tally startup and requires no additional runtime, middleware, or background service. PrecisionTech has been developing TDL solutions for over 15 years, building hundreds of addons across every industry vertical in India.

These three terms represent different scopes of TDL work. A TDL Addon is a self-contained add-on module that adds a specific new capability to Tally — for example, a WhatsApp notification addon, a barcode printing addon, or an auto e-Invoice addon. These are typically packaged as TCP files and can be installed on any Tally installation without altering its core configuration. A TDL Customisation is a deeper modification of Tally's existing behaviour — for instance, changing the layout of an invoice, adding mandatory custom fields to a voucher, enforcing business-specific validation rules, or restructuring balance sheet formats. A TDL Integration goes further by connecting Tally with external systems — pushing or pulling data between Tally and your ERP, CRM, e-commerce platform, government portals (GST, e-Way Bill, e-Invoice), banking API, or any REST/SOAP service — using TDL's HTTP capabilities or file-based exchange formats. PrecisionTech delivers all three categories and often combines them to build complete end-to-end solutions tailored to your workflows.

Yes. TallyPrime introduced an enhanced TDL 2.0 framework with many new capabilities including improved HTTP functions, enhanced XML handling, better event handling, and expanded report definitions. PrecisionTech's TDL Addons are built and tested specifically against the current stable release of TallyPrime. If you are migrating from Tally ERP 9 to TallyPrime, we offer a TDL migration and upgrade service where we review your existing TDL files, update deprecated functions, rewrite incompatible sections, and validate the addon against the latest TallyPrime build. This ensures zero disruption to your business workflows during your upgrade. We also support TallyPrime TSS subscribers who need addons to keep pace with Tally's periodic feature releases such as new GST return formats, e-Invoice API version changes, and updated payroll rules.

Absolutely. TDL Addons are stored as TCP (Tally Compiled Program) files and are loaded directly by the Tally application at startup. Because on a Cloud VPS the full TallyPrime application runs on the server, all TDL Addons function identically on the cloud as they do on a local desktop. PrecisionTech is uniquely positioned to serve you in this regard because we offer both Tally on Cloud VPS and TDL Addon development under one roof. When you purchase a TDL Addon from us and you are also a Tally Cloud VPS customer, we deploy the addon directly to your VPS and test it live — so there is no back-and-forth with a third party. For cloud customers, we also build addons specifically optimised for multi-user concurrent environments, ensuring no locking conflicts or data race conditions occur when multiple users access Tally simultaneously on the shared VPS session.

TDL's report-building capability is extremely powerful and covers virtually any financial, operational, or analytical report your business needs. Common reports PrecisionTech builds include: multi-branch consolidated P&L and Balance Sheet, party-wise ageing analysis (with configurable buckets and colour-coded alerts), item-wise profitability reports, salesperson/region-wise performance dashboards, GST Input vs. Output reconciliation statements, pending order fulfillment tracking, customer credit utilisation reports, daily/weekly sales flash reports with comparison to budget, PDC (Post-Dated Cheque) inflow/outflow calendars, GSTR-1 vs. book summary reconciliation, and manufacturing batch cost variance reports. All these reports are accessible from within Tally's menu just like native reports — no export or third-party tool required. Reports can be exported to Excel, PDF, or printed with custom branding including your company letterhead and logo applied automatically via TDL print formatting.

Yes, and this is one of the most popular and ROI-positive categories of TDL work we do. Using TDL's built-in HTTP Post functions and event triggers, PrecisionTech can build addons that automatically send WhatsApp messages (via WhatsApp Business API or approved gateways like Interakt, Wati, or 2Factor), SMS alerts (via any HTTP SMS gateway), or templated emails — all triggered directly from within Tally on actions such as: invoice saved, payment received, purchase order raised, overdue reminder due, stock level falling below reorder, payslip generated, or job completion. For example, when a salesperson saves an invoice in Tally, the addon can instantly dispatch a WhatsApp message to the customer with the invoice PDF attached and a payment link embedded — without any manual step. Similarly, when your accounts team marks a customer as overdue, the system can fire personalised payment reminder SMS and email to the contact. These automations eliminate manual follow-up effort, reduce collection cycles, and dramatically improve customer communication quality.

Excel import is one of the most frequently requested TDL capabilities and PrecisionTech has developed robust, field-tested importers across dozens of use cases. The TDL-based Excel import works by reading a structured XML or CSV intermediate file and creating Tally vouchers, masters, or data records programmatically. Common import scenarios we deliver include: bulk sales invoice import from e-commerce platforms (Shopify, WooCommerce, Amazon, Flipkart), purchase invoice import from vendor portals, salary voucher upload from HR systems, bank statement import for reconciliation, opening stock and ledger balances import for new Tally company setup, and GST data import from government portals. We build the importer as a fully native TDL Addon — the user simply places the Excel/CSV file in a designated folder, opens a custom Tally menu item, and the addon processes, validates, and imports the data with a full exception report. No third-party middleware, no Java runtime, no Excel add-in required — it all runs inside Tally.

Yes. TDL supports HTTP/HTTPS communication natively, which means it can call REST APIs directly, send and receive JSON or XML payloads, and post data to any web service — all from within the Tally engine without external middleware. PrecisionTech has built integrations between Tally and: SAP (for subsidiary-to-parent data sync), Salesforce CRM (syncing invoices, receipts, and customer balances), Zoho CRM & Zoho Books (order-to-invoice workflow), WooCommerce and Shopify (auto-creating Tally sales entries from online orders), Unicommerce (inventory and order management sync), Amazon Seller Central (settlement reconciliation), Flipkart (commission and returns reconciliation), Razorpay and PayU (payment reconciliation into Tally), banking portals via SFTP/API for bank reconciliation, and various government portals (GSTN, NIC e-Invoice, e-Way Bill). For larger integrations, we pair TDL with a lightweight PHP/Python microservice that handles API authentication and data transformation, while TDL handles the read/write inside Tally — giving you the best of both worlds.

Development timelines depend on the scope and complexity of the addon. Simple enhancements — such as adding custom fields to a voucher, modifying the invoice print format, or enabling auto-calculation in a report — are typically completed in 2 to 5 business days. Mid-complexity addons such as WhatsApp notification integration, Excel importer for a specific voucher type, or a custom ageing report take 1 to 3 weeks including design, coding, testing, and deployment. Complex addons involving multi-system integrations, approval workflows, or entirely new sub-modules within Tally take 3 to 8 weeks. PrecisionTech follows a structured development process: requirement gathering → functional specification document → prototype/demo → development → internal testing → client UAT (User Acceptance Testing) → deployment → post-live support. We provide a functional specification document before starting coding so you can review and approve exactly what will be built. This eliminates misunderstandings and ensures the delivered addon matches your business process precisely.

Yes. When TDL source code is compiled into a TCP (Tally Compiled Program) file, the source is obfuscated and encrypted within the binary. End users cannot view, extract, or modify the TDL logic from a TCP file. Additionally, PrecisionTech can implement Tally's built-in site licensing mechanism, which locks the TCP file to specific Tally account IDs (TallyPrime account serial numbers). This means the addon will only activate on the licensed Tally installation and will not function if copied to an unlicensed system. For clients who purchase our custom TDL addons under a commercial licence, we provide the TCP file along with a licence agreement. Clients who purchase custom TDL development as a work-for-hire project receive the full source code and unrestricted ownership. We are transparent about IP ownership from day one and document it clearly in our project agreement before work begins.

Well-written TDL Addons that follow Tally's published development guidelines and use stable, non-deprecated APIs rarely break on minor Tally updates. Tally Solutions typically maintains backward compatibility for TDL functions across releases. However, major version upgrades (e.g., from Tally ERP 9 to TallyPrime, or between major TallyPrime releases) can introduce breaking changes — especially for addons that relied on internal functions, specific report structures, or older HTTP handling methods. PrecisionTech mitigates this by: writing addons against stable TDL APIs, avoiding undocumented internal functions, and maintaining an archive of all TDL source code for every client. When Tally releases a major update, we proactively review our addons for compatibility and notify clients of any required updates. Clients on our Annual Maintenance Contract (AMC) receive free compatibility updates for all addons developed by us during the AMC period. We strongly recommend AMC for any business-critical TDL Addon to ensure uninterrupted operation through Tally's update cycle.

Yes, this is a service we offer called TDL Audit and Rescue. Many businesses find themselves with TDL Addons that were written by a freelancer or former IT vendor who is no longer available, and these addons have become incompatible with a new TallyPrime version, are crashing Tally, are producing incorrect output, or are simply not doing what was originally intended. PrecisionTech can decompile or review the original TDL source file (if you have it), audit the logic, identify bugs or incompatibilities, and rebuild or fix the addon. If you do not have the source — only a TCP file — we can rebuild the addon functionality from scratch based on your current business requirements. Our TDL Audit service includes a written report detailing what the existing addon does, what is broken, and what changes are needed — giving you a clear picture before we start any paid work.

PrecisionTech's most popular ready-made TDL Addons span several categories. In communications: the WhatsApp Invoice Sender (auto-sends invoice PDFs to customers via WhatsApp), Tally Email Automation (invoice + statement emailer with attachment), and SMS Payment Alert (instant SMS on receipt). In compliance: Auto e-Invoice from Tally (generates IRN/QR via IRP without leaving Tally), GSTR-2B Reconciliation (auto-matches ITC claims with portal data), and e-Way Bill Generator. In data management: Excel Multi-Voucher Importer, Bulk Ledger Creator, and Stock Master Excel Importer. In operations: Salesman-wise Commission Calculator, Vehicle/Route-wise Delivery Tracker, PDC Management Dashboard, Approval Workflow for Vouchers, and Multi-Branch Dashboard. In printing: Custom Invoice Designer (thermal, A4, A5), Delivery Challan with Barcode, and Label Barcode Printer. Each ready-made addon is offered as a fully tested TCP file with installation support and a user guide.

Yes. Multi-branch operations are one of the most complex and high-value use cases for TDL. By default, Tally manages each branch as a separate company (separate data file). PrecisionTech's multi-branch TDL suite addresses this by building: an inter-company data sync engine (transfers vouchers between branch and HQ Tally files automatically over LAN, VPN, or the internet), a consolidated P&L and Balance Sheet report that pulls live data from multiple Tally files and presents them in a single merged report with branch-wise columns, branch-wise stock transfer voucher with built-in approval, and a head-office dashboard showing outstanding receivables, payables, and sales across all branches in one screen. For businesses on Tally Cloud VPS, we can also set up a multi-company hosted environment where all branches share a centralised VPS, eliminating the sync problem entirely since all data is live on one server. PrecisionTech has delivered multi-branch TDL solutions for clients with 3 to 40+ branches across India.

Pricing for TDL work at PrecisionTech is structured in two ways. Ready-made TDL Addons are priced on a per-addon or per-bundle basis: individual addons (e.g., WhatsApp Sender, e-Invoice Auto-Generator) are available from ₹1,999 onwards. Business packs bundling 3–5 popular addons start from ₹4,999. Custom TDL Development is priced based on scope: simple enhancements start at ₹4,999, mid-complexity projects (full workflow addon, complex integration) range from ₹14,999 to ₹49,999, and large enterprise-grade custom suites are quoted on a project basis after a detailed requirements workshop. All custom development includes a functional spec, development, testing, deployment, and 30-day post-go-live support. Annual Maintenance Contracts (AMC) for maintaining and updating your TDL addons start at ₹4,999/year and include free compatibility updates, bug fixes, and a set number of minor enhancement requests. Contact PrecisionTech for a no-obligation quote — we evaluate your requirement and give you a fixed-price proposal with clear deliverables.

Yes, and this is a transformative capability for growing businesses. TDL can intercept the save action of any voucher, validate it against any set of business rules, and either block saving (with an error message) or trigger a secondary workflow before the voucher is finalised. PrecisionTech builds approval workflow addons that enforce multi-level purchase order approvals (where purchase vouchers above a set value require manager sign-off before they are posted), sales return approval (where credit notes require accounts head authorisation), payment authorisation workflows (where cheque/NEFT payments require dual approval before the voucher is unblocked), and budget utilisation validation (where expense vouchers that exceed the department budget are blocked or flagged). These workflows are managed entirely within Tally — no email, no separate system needed — using TDL-defined status fields (Pending / Approved / Rejected) visible to relevant users. Combined with Tally's user security roles, these addons give you granular control over who can do what in your Tally system.

Absolutely. GST compliance is one of the most critical and time-consuming areas where TDL Addons deliver enormous value. PrecisionTech's GST-focused TDL suite includes: Auto e-Invoice Generation — which connects directly to the IRP (Invoice Registration Portal) API and embeds the IRN and QR code into Tally without manual data entry or switching applications; GSTR-1 Validation Addon — which pre-validates your outward supply data against GST rules before you file, catching GSTIN mismatches, invalid HSN codes, missing e-Invoice references, and rate errors; GSTR-2B Auto-Reconciliation — which downloads portal data, matches it against your Tally purchase records, and highlights discrepancies for your team to action; e-Way Bill Auto-Generator — which creates e-Way Bills directly from Tally delivery challans or invoices via the NIC API and embeds the EWB number back into the Tally voucher; and RCM Tracker for import and reverse-charge entries. These addons save accounts teams 10–20 hours per month while dramatically reducing filing errors and ITC mismatches.

TDL Addons deliver value across virtually every industry that uses Tally, but the sectors where PrecisionTech sees the highest ROI from TDL customisation include: Manufacturing — where Bill of Materials, batch/lot tracking, production vouchers, scrap reporting, and quality hold workflows are critical needs not covered by standard Tally; Retail & Distribution — where POS integration, barcode printing, scheme/discount management, and route-wise delivery tracking are essential; Pharmaceuticals & Healthcare — where expiry-date management, Schedule H drug registers, and patient/prescription tracking are regulatory requirements; Real Estate & Construction — where project-wise cost tracking, milestone billing, subcontractor payment management, and percentage-of-completion revenue recognition require custom Tally workflows; Education — where fee structure management, instalment tracking, scholarship adjustments, and student-ledger statements are needed; Export / Import — where multi-currency, foreign bank reconciliation, shipping bill tracking, and duty drawback calculations need TDL extensions; and E-commerce aggregators — where marketplace settlement reconciliation across Flipkart, Amazon, Meesho, and own website orders requires automated import addons.

TDL is a domain-specific, declarative language — quite different from procedural or object-oriented languages like Python, Java, or C#. Instead of writing step-by-step instructions, TDL works by defining objects (reports, fields, collections, functions, forms, menus, keys) that describe what should exist and how it should behave, and Tally's engine handles the execution. This makes TDL very concise and powerful for Tally-specific tasks but means general programmers need significant TDL-specific training to be effective. TDL has its own syntax, its own data model (aligned with Tally's internal objects), and its own event model. A 10-line TDL definition can create a fully functional, dynamic report that would take hundreds of lines of code in a general-purpose language using ODBC or file access. PrecisionTech's TDL developers hold deep specialised expertise in TDL — not just general programming — which is why businesses trust us with complex, business-critical Tally customisations rather than a generic IT vendor or freelance programmer who has learned TDL superficially.

PrecisionTech follows a rigorous quality assurance process for every TDL Addon we deliver. After development, every addon goes through: Unit testing — testing each defined component (report, field, function) in isolation; Integration testing — testing the addon within a full TallyPrime installation with realistic data including edge cases (zero quantities, negative values, special characters in party names, multi-currency entries, backdated vouchers); Multi-user stress testing — for addons deployed on Cloud VPS with multiple concurrent users; and UAT (User Acceptance Testing) — conducted by the client on their own test company before we deploy to production. Post-delivery, every client receives 30 days of free support for any bugs in the delivered scope. For ongoing support, our TDL AMC (Annual Maintenance Contract) provides unlimited bug fixes, compatibility updates for new Tally releases, minor enhancement requests, and a dedicated WhatsApp support channel. We also maintain a detailed change log for every addon version, so you always know exactly what changed and when.

Yes. Invoice and document formatting is one of the most common and immediately visible TDL customisation types. TDL gives complete control over every aspect of printed and PDF output from Tally: layout (portrait/landscape, thermal, A4, A5, multiple columns), fonts, borders, background shading, logos, QR codes, barcodes, custom fields (such as your bank account details, MSME registration number, transport details, or special terms), multi-language printing (English + Hindi or English + regional language side by side), conditional formatting (e.g., print "TAX INVOICE" if GSTIN present, else "BILL OF SUPPLY"), dynamic tables with variable row heights, and custom totals or sub-totals. PrecisionTech has designed and delivered over 200 unique invoice formats for clients across industries — from simple retail cash memo formats to complex project-specific billing formats with detailed breakdowns, multi-page continuation sheets, and client-specific field arrangements. We can replicate your existing word processor invoice format exactly within Tally so all your printed documents look consistent and professional.