# Vertex O Series vs Zamp (slim)

> Vertex O Series scores 54.7 (C) on agent readiness against Zamp's 49.5 (D), and leads in 4 of 7 scored categories. Zamp leads on reliability, agent ergonomics and payments & pricing. Both do tax calculate. Category scores, facts, verdicts and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/vertex-tax-vs-zamp.md (~2,300 tokens) · this version ~680 tokens · JSON https://www.anchorterminal.com/compare/vertex-tax-vs-zamp.json · canonical https://www.anchorterminal.com/compare/vertex-tax-vs-zamp
- Index: https://www.anchorterminal.com/llms.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 Zamp's 49.5 (D), and leads in 4 of 7 scored categories. Zamp leads on reliability, agent ergonomics and payments & pricing. Both do tax calculate.

- Vertex O Series: C 54.7, rank #526 of 722 · https://www.anchorterminal.com/tools/vertex-tax.min.md
- Zamp: D 49.5, rank #609 of 722 · https://www.anchorterminal.com/tools/zamp.min.md
- Vertex O Series, 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 Schema & documentation, 74 against 44; Security & auth, 57 against 40; Maintenance & community, 62 against 42; Transparency & trust, 68 against 50.
- Zamp, good for An agent working for a US or Canadian seller that wants Zamp's team to register, file and remit, and needs calculation and transaction sync through a small API. Ahead on Reliability, 72 against 65; Agent ergonomics, 64 against 51; Payments & pricing, 20 against 0. Also Free to start without a card.

| Category | Vertex O Series | Zamp |
| --- | --- | --- |
| Reliability (16%) | 65 | 72 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 74 | 44 |
| Agent ergonomics (13%) | 51 | 64 |
| Security & auth (14%) | 57 | 40 |
| Payments & pricing (10%) | 0 | 20 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 62 | 42 |
| Transparency & trust (7%) | 68 | 50 |

| Fact (where they differ) | Vertex O Series | Zamp |
| --- | --- | --- |
| Vendor | Vertex, Inc. | Zamp Inc. |
| Hosted endpoint | `https://calcconnect.vertexsmb.com/vertex-ws/v2` | `https://api.zamp.com` |
| Auth | OAuth | API key |
| Licence | Proprietary service under a customer agreement with Vertex, Inc. that isn't published | Proprietary service under Zamp's Standard Terms and Conditions, which form part of a signed Order Form. The sandbox has its own Developer trial terms |
| llms.txt | no | yes |
| Last release | 2026-09-25 | 2026-08-31 |
| Privacy policy last updated | no date given | 2025-02-11 |
| Terms restrict automated access | not found in the text | yes |
| Terms restrict benchmarking | not found in the text | yes |