Reverse Charge Mechanism: RCM Calendar for Startups and MSMEs
A monthly reverse-charge calendar for legal, GTA, director, renting, security, imported services and notified unregistered-supplier transactions.
RCM failures usually start in vendor onboarding because the invoice arrives without GST and looks like a non-tax item.
Section 9(3) applies reverse charge to notified categories; section 9(4) applies only to notified persons and supplies rather than every unregistered purchase.
RCM tax is ordinarily discharged in cash and eligible credit is considered separately.
Time-of-supply rules differ for RCM goods and services.
Self-invoice and payment-voucher requirements can apply where the notified supplier is unregistered.
What the business should understand
- Section 9(3) applies reverse charge to notified categories; section 9(4) applies only to notified persons and supplies rather than every unregistered purchase.
- RCM tax is ordinarily discharged in cash and eligible credit is considered separately.
- Time-of-supply rules differ for RCM goods and services.
- Self-invoice and payment-voucher requirements can apply where the notified supplier is unregistered.
- An expense can be subject to both GST RCM and income-tax withholding without one replacing the other.
The five-point review
| Check | What to examine |
|---|---|
| Supply category | Notification entry and current amendment. |
| Supplier | Registration, constitution and option. |
| Recipient | Whether the notified recipient class is met. |
| Timing | Invoice, receipt, payment and book entry. |
| Credit | Business use, 2B/records and blocked-credit test. |
Practical example
A startup pays an individual advocate, a foreign SaaS provider and a security agency. All three invoices show different or no GST. The RCM calendar should classify each transaction under its own notification and recipient conditions rather than apply one general ‘vendor unregistered’ rule.
How to apply the framework
Tag RCM vendors and GL accounts in ERP, but allow a transaction override because vendor identity alone may not determine tax.
At month end, reconcile the RCM register to expenses, vendor advances, import remittances and GSTR-3B. Track delayed tax and interest separately from credit.
Decision workflow
Define the legal question before changing the return
Identify the GSTIN, tax period, transaction, document and exact statutory question. Review supply category, supplier and recipient together. Freeze the source data so that later ERP edits do not destroy the evidence used for the decision.
Reconcile from commercial reality to portal data
Start with the contract or commercial event. Move through the invoice, receipt or movement evidence, e-invoice or e-way bill, accounting entry, return and electronic ledger. Classify each difference as timing, error, ineligible amount, statutory exception, disputed position or completed correction. Avoid a plug entry whose only purpose is to make two reports equal.
Record the conclusion and future control
Prepare a concise position note with facts, authority, amount, alternative view and approval. Preserve the filing acknowledgement and update the responsible master data, vendor rule, invoice workflow or monthly checklist. The objective is not only to survive one review but to prevent the same issue in the next period.
Action checklist
- Maintain a current notification matrix.
- Tag vendors and expense codes.
- Calculate time of supply.
- Prepare self-invoice/payment voucher where required.
- Pay RCM in cash.
- Claim credit only after eligibility review.
Evidence to keep
- Vendor contract and invoice
- RCM notification memo
- Self-invoice/payment voucher
- Cash-ledger payment
- ITC and GSTR-3B reconciliation
Warning signs
- Every unregistered purchase put under RCM
- Supplier’s GSTIN treated as complete answer
- RCM paid with ITC
- Foreign services omitted
- Equal credit used to ignore interest
Finin2min takeaway
GST positions are strongest when the transaction, legal provision, invoice, physical or service evidence, books, return and electronic ledger agree. A portal match without commercial evidence is not a complete control.