Getting Into the GM Vendor Service Portal
The General Motors Vendor Service Portal, commonly called VSP, is where suppliers handle purchase orders, submit invoices, register as a vendor, and track payment status. It is not user-friendly by design. The interface hasn't changed meaningfully in years, and the authentication system will occasionally drop your session without warning. I have walked dozens of suppliers through this over the years, and the biggest mistake people make is assuming the login page is the problem when it rarely is. The actual login process involves a SSO redirect chain that passes through GM's identity provider before landing you in the portal. You enter a registered email address, receive a one-time code, and then answer a security question you set up during account creation. If you forgot that security question, you are looking at a support ticket that can take 3 to 5 business days to resolve. I learned this the hard way when a supplier couldn't access their POs right before a quarter-end close and had to manually follow up with GM's supplier helpdesk using their DUNS number and company legal name. Most people skip that and just retry the password reset loop, which does nothing. Here is how the process actually works step by step.
The Login Steps
Navigate to the GM VSP portal at vendor.gm.com. Click sign in and you will be redirected to GM's corporate SSO page. Enter the email address associated with your GM vendor account. If you do not know which email is registered, check any prior invoice acknowledgment email from GM procurement or ask your GM buyer directly. After submitting the email, you will receive a six-digit code. Enter it along with your security question answer. The session typically lasts four hours before requiring re-authentication. If you receive an error stating your account is inactive or restricted, your vendor profile may still be under review. GM sometimes places new suppliers on a provisional status that blocks full portal access until their W-9, insurance documentation, and EDI setup are verified. This can take anywhere from one week to three weeks depending on the complexity of the supplier category. I have seen simpler supplier registrations clear in under five business days, but those are the exception.
Common Problems and Workarounds
The most frequent issue I encounter is browsers blocking the session cookies due to aggressive tracking protection. This is especially common with Brave and Firefox when strict mode is enabled. Switch to Chrome or Edge, clear cookies for the domain, and try again. The portal was built with Internet Explorer-era assumptions and does not handle modern browser privacy defaults well. Another issue is the security question. If you selected a custom question during registration and then forgot the answer, there is no self-service recovery. You must submit a request to the GM Supplier Helpdesk at suppliersupport@gm.com or call their line and reference your supplier ID. Bring your legal entity name, DUNS number, and a recent purchase order number if you have one. Without at least two of those three identifiers, they cannot verify your identity and the ticket goes nowhere. I ran into a specific edge case last year where a supplier's primary contact email had changed after a company restructuring, but the VSP account was still tied to the old address. The existing team tried to reset passwords for weeks with no success because the reset link never arrived. The workaround was having their GM buyer update the contact record on the Procurement side first, which then allowed the VSP account to sync and accept the new email. This is not documented anywhere in the help articles. Suppliers usually spend two to three days stuck before someone figures this out.
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What You Can Actually Do Once Logged In
Once you are through the portal, the main functions are viewing and acknowledging purchase orders, submitting invoices through the electronic invoicing module, downloading remittance advice after payment is processed, and updating your company profile information. The invoice submission module requires specific formatting. If your invoice does not include the PO number in the exact format GM issued it, the system rejects it automatically and there is no preview step. I recommend saving a copy of every submission with a timestamp before you hit confirm. The portal also has a document center where suppliers can upload compliance certificates, insurance cards, and audit responses. Files over ten megabytes will fail to upload silently. There is no progress bar or error message, just a spinning icon that eventually times out. Resize your PDFs first.
Limitations and Realistic Expectations
The VSP portal has significant downtime during GM's fiscal quarter close periods, usually the first two business days of the month. Payment status updates often lag by 48 to 72 hours even when payments have already been processed in the backend. Do not refresh the page obsessively expecting real-time accuracy. The search function for old POs is limited to the last twelve months unless you export data, and even the export is clunky. I usually tell suppliers to run quarterly exports of their transaction history rather than relying on the portal as a record-keeping system. Mobile access is essentially non-existent. The portal renders poorly on any screen smaller than 1280 pixels wide. If you need to check something on the go, use a laptop or desktop.
