Handling IRS Outages: TIN Verification Resilience
Baselayer maintains a real-time integration with the Internal Revenue Service (IRS), which enables real-time verification of Taxpayer Identification Numbers (TINs) against corresponding business or individual names. This ensures maximum accuracy, timeliness, and coverage in our verification process. A known and infrequent issue involves temporary unavailability of the IRS platform used for TIN verification. We commonly refer to these instances as IRS outages. Being aware of these potential scheduled or unscheduled outages can help in planning and mitigating disruptions when using the IRS TIN verification. This guide explains how Baselayer handles these situations automatically and how to build resilient verification workflows that gracefully handle temporary TIN validation unavailability. TIN Check uptime is available in our status page - which provides an overview of our API, Console and TIN Match availability.Baselayer System Behavior During IRS Outages
If a TIN is provided in the search input and the IRS TIN Matching service is unavailable at the time of processing, Baselayer will continue with all other parts of the verification process and notify clients accordingly, returning all available data except the TIN verification status. The response explicitly states that the IRS service was unavailable at the time of the request.Webhook Behavior During Outage
- Webhook Type:
BusinessSearch.completedorBusinessSearch.failed - TIN Status Field:
tin_matched = null
- Warnings Field:
warnings = "IRS Validation is unavailable."
Webhook Behavior After Outage Resolution
- Once the IRS TIN Matching service becomes available again, Baselayer will automatically retry validation of previously failed TIN checks.
- Upon successful validation, an updated webhook is sent:
- Webhook Type:
BusinessSearch.updated - TIN Status Field:
tin_matched = true/false(based on actual IRS response)
- Warnings Field:
- Omitted if validation is successful.
- Webhook Type:
Retry Logic & Queue Management
During an IRS outage, all business searches where IRS TIN validation was not possible are placed into a retry queue. Baselayer initiates an automated retry sequence to reattempt verification. Retries are performed every 15 minutes for up to about 24 hours. If noBusinessSearch.updated webhook arrives after that, retries have stopped and tin_matched stays null. Retries occur sequentially to manage load and avoid redundant requests.
Once the IRS service is restored, Baselayer automatically reprocesses any previously incomplete TIN verifications, updates the associated records, and notifies the affected customer systems with the completed information.
Illustrative Example Timeline
This example demonstrates Baselayer’s automatic retry behavior during a transient IRS outage. The key takeaway: you only need to handle the webhooks - Baselayer manages all retry logic automatically.Expected Frequency of IRS Outages
The IRS conducts routine maintenance on its e-Services platform, which includes the TIN Matching service. While the IRS does not provide a detailed schedule of all maintenance periods, these outages are usually brief and scheduled during off-peak hours to minimize disruption. The most common maintenance window is on Sundays from 12:00 a.m. to 4:00 p.m. ET. In addition, the IRS infrequently faces unscheduled outages in the IRS TIN matching service, causing high rates of failure. While metrics are not officially tracked, based on Baselayer’s experience and monitoring the estimated frequency of unscheduled outages is:- Mild to moderate disruptions - intermittent failures or degraded service - occur 1-2 times per quarter
- Major outages - where the service is entirely down or timing out consistently for +2 hours - appear to occur 1-2 times per year
Decisioning Strategies During IRS Outages
Whentin_matched = null due to an IRS outage, you’ll need a strategy for handling the application. Based on your risk tolerance and product requirements, here are two common approaches Baselayer customers use:
Strategy 1: Stop & Wait
Approach: Halt the application immediately and wait for IRS validation to complete before making any decision. How it works:- High-risk products (lending, large credit lines)
- Regulated financial institutions with strict compliance requirements
- Products where TIN validation is mandatory for regulatory reasons
Strategy 2: Conditional Approval
Approach: Approve the application provisionally based on all other verification checks, then monitor the TIN result when it arrives. How it works:- Low-risk products (marketplaces, basic accounts, vendor onboarding)
- Products where speed-to-activation drives conversion
- Customers with strong fraud controls beyond TIN (device signals, identity network, transaction monitoring)
- Requires account freeze capabilities
- Needs fraud team workflows for post-approval TIN failures
- More complex to implement but better conversion
- Consider limiting functionality until TIN validates (e.g., “Lite Profile”)
Choosing Your Strategy
Recommendation: Most Baselayer customers use Stop & Wait as it provides the cleanest customer experience and simplest operational workflow. The delay is typically under 1 hour, which is acceptable for most products.
Use Conditional Approval only if:
- You have robust secondary fraud controls beyond TIN validation
- Conversion rate is critical to your business model
- You can operationally handle account freezes and customer reverification
- Your risk profile allows for some exposure before full TIN validation
Testing IRS Outage Scenarios
Baselayer provides a sandbox test case that simulates IRS outage behavior, allowing you to validate your webhook handling and retry logic.Test Case Setup
Use these exact inputs in sandbox:Expected Behavior
Initial Response (immediate):- Webhook:
BusinessSearch.completed - Fields:
tin_matched: nullwarnings: ["IRS Validation is unavailable."]state: "COMPLETED"
- Webhook:
BusinessSearch.updated - Fields:
tin_matched: trueorfalse(actual validation result)warnings: [](empty, validation succeeded)- All other fields remain the same
What to Verify in Your Tests
✅ Initial webhook handling: Your system correctly processestin_matched: null according to your chosen strategy
✅ Status tracking: Application status is properly recorded and can be updated later
✅ Updated webhook handling: Your system receives and processes BusinessSearch.updated events
✅ Decisioning logic: Final approval/decline decision correctly incorporates the TIN validation result
✅ User notifications: Customers receive appropriate messages based on your strategy (pending vs. approved vs. review)
Best Practices
Monitor IRS Availability
- Check Baselayer Status Page for real-time TIN check availability
- Subscribe to status page notifications for proactive alerts
- Monitor your own
tin_matched: nullandwarningsrates to detect emerging issues
Webhook Handling
- Always check both
tin_matchedandwarningsfields to distinguish IRS outages from invalid TINs - Process
BusinessSearch.updatedevents idempotently (retries may cause duplicates) - Log all webhook events for debugging and audit trails
Establish a Clear Policy
- Document your IRS outage strategy for compliance audits
- Train support and operations teams on expected behavior
- Set SLAs for resolving pending applications (e.g., 4 hours max during business hours)
Next Steps
Understand verification workflows:- Business Search: Basics - How TIN verification fits into KYB
- Business Search: Best Practices - Complete decision logic including TIN validation
- Scores & Ratings - How TIN impacts KYB ratings
- Webhooks at Baselayer - Complete webhook integration guide
- Business Search: API Quickstart - Understanding Business Search responses
- Sole Proprietorship Verification - When to rely on TIN validation alone
- Business Search: Best Practices - Rules-based verification with TIN as one factor