Short answer: Under GST’s Invoice Management System (IMS), every supplier invoice in your IMS inbox needs a decision: Accept, Reject or Pending. If you do nothing, the invoice is deemed accepted when GSTR-2B is generated on the 14th. GST IMS Inbox by Vayasoft brings your IMS download into Odoo 19 and matches it to your vendor bills in both directions. You see what to accept, what to hold, and which bills never reached the portal, all before the 14th.
What is GST IMS, and why does it matter?
IMS is the GST portal’s inbox for supplier invoices. Your suppliers’ invoices appear there, and you mark each one as Accept, Reject or Pending. Those decisions feed your GSTR-2B and, from there, the input tax credit (ITC) you can claim.
The catch is that the portal can only see the supplier’s side. It doesn’t know whether the goods arrived, whether the amount matches your purchase order, or whether you’ve booked the bill. That information sits in Odoo.
Why reconcile IMS inside Odoo?
Most tools check one direction. GST IMS Inbox checks both:
| Situation | What it means | What the app does |
|---|---|---|
| In IMS, not in Odoo | The supplier filed it, but your books don’t have it | One click drafts the vendor bill, with tax applied when the split is clear |
| In Odoo, not in IMS | You booked a bill the supplier never uploaded, so the ITC isn’t claimable yet | One click emails the vendor, once, with no accidental repeats |
| In both, amounts differ | A mismatch to check before accepting | Flags Amount Differs and suggests Pending |
| In both, amounts match | Safe to accept | Suggests Accept, with an Apply All shortcut |
The app never suggests Reject. Rejecting is always your decision.
How do I use GST IMS Inbox?
- Download your IMS data from the GST portal, as CSV, Excel or the bulk ZIP. The app detects the format automatically.
- Import it into Odoo. Each import is stored by period and company, so you can reopen any past month.
- Review the dashboard. Filter by decision, match status or GSTN category (B2B invoices, credit notes, debit notes and ECO [9(5)] invoices), and sort by amount.
- Decide in bulk. Select a batch, choose Accept or Pending, and add remarks.
- Notify vendors whose bills are missing from IMS. Each vendor gets one grouped email.
- Export your decisions as an XLSX file in the Offline Tool column order, then act on the portal.
Each decision also shows on the vendor bill itself, so your accounts team doesn’t have to switch screens.
What it doesn’t do yet
The current version doesn’t send decisions to the GST portal for you. You decide in Odoo, then act on the portal. A direct connection through an approved GST Suvidha Provider (GSP) is planned for a later release.
Frequently asked questions
Does it submit Accept, Reject or Pending to the GST portal?
Not yet. There’s no GSP connection in the current release. You decide in Odoo, then act on the portal yourself.
What file formats can I import?
Whatever the portal gives you: CSV, Excel or the bulk ZIP, detected automatically.
Does it ever reject an invoice automatically?
Never. It only suggests Accept or Pending, with a plain-English reason.
Does it work with multiple companies or GSTINs?
Yes. Each import is scoped to its own company.
Which Odoo versions does it support?
Odoo 19, Community and Enterprise.
What happens if I uninstall it?
Everything the app added is removed. Your bills and taxes stay untouched.
Talk to Vayasoft
Running GST accounting in Odoo? Vayasoft sets up Odoo for Indian businesses, including GST, e-invoicing, TDS and vendor reconciliation. Book a free 30-minute call with our Odoo accounting team.
Links: GST IMS Inbox on the Odoo App Store
About Vayasoft: Vayasoft is an official Odoo Ready Partner based in India. We build Odoo apps and implement, upgrade and support Odoo for trading, manufacturing, solar EPC, retail and healthcare businesses.