# Numeral vs Vertex O Series

> Vertex O Series scores 54.7 (C) on agent readiness against Numeral's 49.3 (D), and leads in 4 of 7 scored categories. Numeral leads on schema & documentation, agent ergonomics and payments & pricing. Both do tax calculate. Category scores, facts, verdicts and agent notes side by…

- Canonical: https://www.anchorterminal.com/compare/numeral-vs-vertex-tax
- Markdown: https://www.anchorterminal.com/compare/numeral-vs-vertex-tax.md (~2,300 tokens)
- Slim: https://www.anchorterminal.com/compare/numeral-vs-vertex-tax.min.md (~680 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/numeral-vs-vertex-tax.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-08

Vertex O Series scores 54.7 (C) on agent readiness against Numeral's 49.3 (D), and leads in 4 of 7 scored categories. Numeral leads on schema & documentation, agent ergonomics and payments & pricing. Both do tax calculate.

- Numeral: grade D, 49.3/100, rank #611 of 722. Markdown https://www.anchorterminal.com/tools/numeral.md · JSON https://www.anchorterminal.com/api/v1/tools/numeral.json
- Vertex O Series: grade C, 54.7/100, rank #526 of 722. Markdown https://www.anchorterminal.com/tools/vertex-tax.md · JSON https://www.anchorterminal.com/api/v1/tools/vertex-tax.json

## Which one, for what

### Numeral (D)

Good for: An agent working for a seller or platform that has a Numeral account and needs tax at checkout, committed transactions for filing, and read access to nexus, registrations and filings through MCP.

Ahead on:
- Schema & documentation, 87 against 74
- Agent ergonomics, 71 against 51
- Payments & pricing, 10 against 0

Watch for: No status page, uptime SLA or numeric rate limit was found. The product page says rate limits can be removed on request

### Vertex O Series (C)

Good for: An agent working inside a company that already has an O Series licence, for quotes, invoice tax, tax area lookups and tax configuration across sales tax, use tax and VAT.

Ahead on:
- Reliability, 65 against 25
- Security & auth, 57 against 47
- Transparency & trust, 68 against 45

Watch for: No public price, free tier or self-serve signup. The security guide sends new users to the Vertex sales team for an account


## Score by category

| Category | Weight | Numeral | Vertex O Series | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 25 | 65 | Vertex O Series +40 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 87 | 74 | Numeral +13 |
| Agent ergonomics | 13% (16.2 this run) | 71 | 51 | Numeral +20 |
| Security & auth | 14% (17.5 this run) | 47 | 57 | Vertex O Series +10 |
| Payments & pricing | 10% (12.5 this run) | 10 | 0 | Numeral +10 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 60 | 62 | Vertex O Series +2 |
| Transparency & trust | 7% (8.8 this run) | 45 | 68 | Vertex O Series +23 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **49.3 · D** | **54.7 · C** | |

## Facts side by side

| Fact | Numeral | Vertex O Series |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Numeral Two, Inc. | Vertex, Inc. |
| Hosted endpoint | `https://api.numeralhq.com` | `https://calcconnect.vertexsmb.com/vertex-ws/v2` |
| Transports | HTTP, Streamable HTTP | HTTP |
| Auth | API key | OAuth |
| Pricing | Paid | Paid |
| x402 | no | no |
| Licence | Proprietary service under Numeral's terms of service. The Go, Python and Node SDKs are Apache-2.0 | Proprietary service under a customer agreement with Vertex, Inc. that isn't published |
| Tools exposed | 14 | none |
| Read-only variant documented | yes | no |
| llms.txt | yes | no |
| Last release | 2026-09-15 | 2026-09-25 |
| Terms last updated | no date given | no date given |
| Privacy policy last updated | no document linked | no date given |
| Customer content may train models | not found in the text | not found in the text |
| Terms restrict automated access | not found in the text | not found in the text |
| Terms restrict benchmarking | not found in the text | not found in the text |
| Terms or service can change without notice | not found in the text | not found in the text |
| Arbitration or class-action waiver | yes | not found in the text |
| Popularity | 0 stars, 9 npm/wk, 19 PyPI/wk | none |

## Verdicts

**Numeral.** Docs are written for agents, with a public OpenAPI spec for 32 operations, Markdown pages, llms.txt and a remote MCP server whose 14 tools are read-only by default. No status page, numeric rate limit or SLA was found, the API ignores idempotency keys, and API access is sold on a custom plan after a demo.

**Vertex O Series.** Public OpenAPI 3.0 specs cover calculation, transaction management, tax area lookup and tax configuration, and guides are served as Markdown. Access needs a sales contract. No price, free tier, sandbox signup, calculation rate limit, idempotency key or official SDK was found in the reviewed documentation.

## Before you call either

### Numeral

1. Send `X-API-Version: 2026-03-01` on every call to `https://api.numeralhq.com`. Merchant, platform and certificate endpoints reject requests without it
2. Commit with a stable `reference_order_id`. On `REFERENCE_ORDER_ID_ALREADY_EXISTS` look up the existing transaction, because `Idempotency-Key` is ignored
3. Commit before the calculation's `expires_at`. If it has expired, calculate again and commit the new `calculation_id` with the original `reference_order_id`
4. Send `amount` as the line total in minor units to `/tax/calculations` and as the per-unit price to `/tax/platform/calculations`
5. Start with an `sk_test_` key. Certificate endpoints and MCP certificate tools are live only and answer `TESTMODE_NOT_SUPPORTED` or `live_mode_required`

### Vertex O Series

1. Cache the access token for its 3,599-second life. The standard token endpoint allows 10 requests per 8 hours, and tokenguard.vertexcloud.com returns a cached token
2. Send no `Authorization: Bearer` header to /oauth/token, and put the client id and secret in the body or a Basic header. Credentials in the URL are rejected
3. Set `saleMessageType` to QUOTATION for an estimate. INVOICE is stored for reporting and remittance
4. Call GET /v2/transaction-exists/{transactionid} before retrying a failed INVOICE. No idempotency key is documented
5. Delete, reverse or roll back a Cloud transaction within 90 days of calculation. Later requests can cause calculation errors or duplicates

## Questions

### Which is better for AI agents, Numeral or Vertex O Series?

Vertex O Series scores 54.7 (C) on agent readiness against Numeral's 49.3 (D), and leads in 4 of 7 scored categories. Numeral leads on schema & documentation, agent ergonomics and payments & pricing.

### Do Numeral and Vertex O Series need an API key?

Numeral needs an API key. Vertex O Series uses an OAuth sign-in.

### Can an agent call Numeral and Vertex O Series without installing anything?

Yes. Numeral has a hosted endpoint at https://api.numeralhq.com and Vertex O Series at https://calcconnect.vertexsmb.com/vertex-ws/v2.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/numeral-vs-vertex-tax.json, and with the fewest tokens: https://www.anchorterminal.com/compare/numeral-vs-vertex-tax.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "numeral", "b": "vertex-tax"}`. From a terminal: `anchor compare numeral vertex-tax`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/numeral.json and https://www.anchorterminal.com/api/v1/tools/vertex-tax.json

## Other comparisons with Numeral or Vertex O Series

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- [Anrok vs Vertex O Series](https://www.anchorterminal.com/compare/anrok-vs-vertex-tax.md)
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- [Numeral vs Quaderno](https://www.anchorterminal.com/compare/numeral-vs-quaderno.md)
- [Numeral vs TaxCloud](https://www.anchorterminal.com/compare/numeral-vs-taxcloud.md)
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- [Numeral vs Zamp](https://www.anchorterminal.com/compare/numeral-vs-zamp.md)
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