Vendor Self-Service Portal
Provide vendors with a branded portal to submit invoices, upload compliance documents, view payment history, manage their profile, and track onboarding status.
The Vendor Portal gives your vendors a public, token-based interface to submit invoices, upload onboarding documents, view payment history, check compliance status, and update their profile — all without needing a Muin login.
Overview
Vendors access the portal through a unique link containing a portal token generated by your organization. No account creation is needed.
The portal provides:
- Dashboard — Onboarding progress, pending actions, recent payments, compliance summary
- Invoice Submission — Submit invoices directly with amount, currency, due date, and description
- Document Upload — Upload compliance and onboarding documents (W-9, insurance, licenses)
- Payment History — View completed payments with amounts and invoice references
- Profile Management — Update contact name, email, phone, and address
- Compliance Status — Track which compliance requirements have been met
| Feature | What Vendors See |
|---|---|
| Dashboard | Vendor name, onboarding steps, pending actions, compliance overview |
| Invoice Submission | Form with invoice number, amount, currency, due date, description |
| Documents | List of uploaded documents with type, filename, status, and date |
| Payments | Paid invoices with amount, currency, date, status, and invoice number |
| Profile | Company name, contact name, email, phone, address, tax ID |
| Compliance | Checklist of requirements with met/not-met status |
Generating a Portal Link
As an administrator, you create portal links for each vendor:
- Navigate to Vendors and open the vendor profile
- Click Generate Portal Link
- Muin creates a unique, secure token for this vendor
- Share the link with the vendor via email
The portal URL follows the format: /go/{your-org}/portal/{vendor-token}/dashboard
Vendor Dashboard
When a vendor opens their portal link, they land on the dashboard.
Dashboard Contents
- Vendor Name — The vendor’s organization name
- Onboarding Status — Whether onboarding is complete, with a step-by-step progress view
- Onboarding Steps — Individual steps with completion status (set up via vendor metadata)
- Pending Actions — Items the vendor needs to address
- Recent Payments — Latest completed payments
- Compliance Status — Summary of compliance requirements and current standing
Submitting Invoices
Vendors submit invoices directly through the portal without emailing PDFs.
- Navigate to the Invoices section
- Click Submit Invoice
- Fill in the required fields:
- Invoice Number — Must contain only letters, numbers, dashes, underscores, dots, or spaces
- Amount — Invoice total (greater than zero, up to two decimal places)
- Description (optional) — Brief note about the invoice
- Due Date (optional) — Expected payment date in YYYY-MM-DD format
- Click Submit
After submission, the vendor receives:
- A unique reference number (format:
VP-{date}-{invoice}-{id}) - A confirmation message that the invoice is pending review
- The submission timestamp
The invoice is created in Muin as a pending record linked to the vendor’s organization, ready for your team’s review and approval.
Uploading Documents
Vendors upload compliance and onboarding documents to meet your requirements.
Supported Document Types
| Type | Description |
|---|---|
| W-9 | Tax identification form |
| Insurance Certificate | Proof of liability coverage |
| Business License | Legal authorization to operate |
| Tax ID | Tax identification documentation |
| Bank Info | Banking details for payments |
| NDA | Non-disclosure agreement |
| Contract | Service agreement |
| Other | Any other supporting document |
Upload Process
- Navigate to the Documents section
- Click Upload Document
- Select the document type from the dropdown
- Choose a file (max 10 MB)
- Click Upload
What Happens After Upload
- The document is stored securely and linked to the vendor’s profile
- If the document type matches an outstanding compliance requirement, that requirement is automatically marked as met
- The vendor’s account manager receives an in-app notification that a document was uploaded
- The document appears in the vendor’s document list with its status
Viewing Uploaded Documents
The Documents tab shows all documents associated with the vendor:
- Document type — Category of the document
- Filename — Original file name
- Status — Processing status
- Upload date — When the document was submitted
Documents are sorted by most recent first, showing up to 50 entries.
Additional Workflows
Viewing Payment History
Vendors can see their completed payments on the Dashboard tab:
- Up to 50 most recent paid invoices showing amount, payment date, status, and invoice number
Updating Vendor Profile
Vendors can update their contact information:
- Navigate to Profile
- View current profile: company name, contact name, email, phone, address, tax ID
- Click Edit
- Update contact name, email, phone, or address
- Click Save
Company name and tax ID are read-only in the portal and can only be changed by your organization’s administrators.
Checking Compliance Status
Vendors monitor their compliance standing on the Dashboard tab:
- Each compliance requirement is listed with its status: Met or Not Met
- The overall status shows either “compliant” (all requirements met) or “action required”
Tips
- Configure onboarding steps — Define onboarding steps in vendor metadata so the portal dashboard shows a clear progress tracker
- Set compliance requirements — Define required document types per vendor so uploading a matching document automatically satisfies the requirement
- Assign account managers — Vendors with an assigned account manager trigger notifications when documents are uploaded
- Use unique invoice numbers — Each invoice number must be unique; duplicate submissions are rejected
- Validate portal tokens — Tokens are checked on every request; if a token is invalid or expired, the vendor sees a clear error message
- Send portal links early — Share the portal link during vendor onboarding so vendors can self-serve from day one
Common Issues
| Issue | Cause | Resolution |
|---|---|---|
| ”Invalid or expired portal token” | The portal token is no longer valid | Generate a new portal link for the vendor |
| Invoice submission rejected as duplicate | An invoice with the same number already exists for this vendor | Use a unique invoice number for each submission |
| Document upload fails with “File too large” | File exceeds the 10 MB limit | Reduce file size or compress the document |
| ”Invalid document_type” error | The submitted document type is not in the allowed list | Choose from: w9, insurance_certificate, business_license, tax_id, bank_info, nda, contract, other |
| Compliance status shows “unknown” | No compliance requirements have been configured for this vendor | Set up compliance requirements in the vendor’s profile |
| Payment history is empty | No invoices have been marked as paid for this vendor | Process pending invoices through your accounts payable workflow |
| Profile update not reflecting | Portal metadata update may need a page refresh | Refresh the portal page to see updated profile information |
Related Features
- Vendor Directory & Compliance — Core vendor management, compliance tracking, and risk scoring
- Vendor Verification — SAM.gov and identity verification for vendors
- Procurement — Purchase orders and catalog management
- Documents — Document processing and intelligence
Need Help?
If you have questions about the Vendor Portal, use the Help button in the bottom-right corner of the app or contact your organization’s Muin administrator.