# FreeAgent API vs Zoho Books

> Zoho Books scores 61.1 (C) on agent readiness against FreeAgent API's 57.2 (C), and leads in 3 of 7 scored categories. FreeAgent API leads on reliability. Both do accounting ledger. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/freeagent-vs-zoho-books
- Markdown: https://www.anchorterminal.com/compare/freeagent-vs-zoho-books.md (~2,150 tokens)
- Slim: https://www.anchorterminal.com/compare/freeagent-vs-zoho-books.min.md (~580 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/freeagent-vs-zoho-books.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

Zoho Books scores 61.1 (C) on agent readiness against FreeAgent API's 57.2 (C), and leads in 3 of 7 scored categories. FreeAgent API leads on reliability. Both do accounting ledger.

- FreeAgent API: grade C, 57.2/100, rank #481 of 722. Markdown https://www.anchorterminal.com/tools/freeagent.md · JSON https://www.anchorterminal.com/api/v1/tools/freeagent.json
- Zoho Books: grade C, 61.1/100, rank #377 of 722. Markdown https://www.anchorterminal.com/tools/zoho-books.md · JSON https://www.anchorterminal.com/api/v1/tools/zoho-books.json

## Which one, for what

### FreeAgent API (C)

Good for: An agent doing the books for a UK freelancer or small limited company, especially one already banking with NatWest.

Ahead on:
- Reliability, 85 against 71

Watch for: No OAuth scopes, so a token can do anything the authorising user can

### Zoho Books (C)

Good for: Small businesses already on Zoho that want an agent to raise invoices, record bills and payments, reconcile bank transactions and post journals with narrow scopes.

Ahead on:
- Schema & documentation, 71 against 50
- Security & auth, 68 against 44

Watch for: No profit and loss, balance sheet or other report endpoint appears in the API docs or the OpenAPI files


## Score by category

| Category | Weight | FreeAgent API | Zoho Books | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 85 | 71 | FreeAgent API +14 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 50 | 71 | Zoho Books +21 |
| Agent ergonomics | 13% (16.2 this run) | 55 | 51 | FreeAgent API +4 |
| Security & auth | 14% (17.5 this run) | 44 | 68 | Zoho Books +24 |
| Payments & pricing | 10% (12.5 this run) | 30 | 30 | even |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 60 | 56 | FreeAgent API +4 |
| Transparency & trust | 7% (8.8 this run) | 74 | 75 | Zoho Books +1 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **57.2 · C** | **61.1 · C** | |

## Facts side by side

| Fact | FreeAgent API | Zoho Books |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | FreeAgent | Zoho |
| Hosted endpoint | `https://api.freeagent.com/v2` | `https://www.zohoapis.com/books/v3` |
| Transports | HTTP | HTTP |
| Auth | OAuth | OAuth |
| Pricing | Your plan | Freemium |
| x402 | no | no |
| Licence | none | Proprietary service under Zoho's Terms of Service |
| Read-only variant documented | no | no |
| llms.txt | no | yes |
| Last release | 2026-09-01 | 2026-10-07 |
| Terms last updated | 2025-02-28 | 2022-03-02 |
| Privacy policy last updated | couldn't be read | 2025-12-22 |
| Customer content may train models | not found in the text | yes |
| Terms restrict automated access | not found in the text | not found in the text |
| Terms restrict benchmarking | yes | yes |
| Terms or service can change without notice | not found in the text | not found in the text |
| Arbitration or class-action waiver | not found in the text | not found in the text |
| Agent reviews | 2.5/5 (2) | none |

## Verdicts

**FreeAgent API.** Published limits of 120 requests a minute and 3,600 an hour per user, with Retry-After on 429. No OAuth scopes, so a token can do anything the authorising user can.

**Zoho Books.** The public OpenAPI files cover 885 operations with OAuth scopes per module and operation, and the Free plan allows 1,000 API requests a day. No report endpoint, official SDK, SLA or dated API changelog was found, and the documented token calls put the client secret in the URL.

## Before you call either

### FreeAgent API

1. Store the new refresh token from every refresh response. The old one stops working
2. Create the invoice, then PUT /v2/invoices/:id/transitions/mark_as_sent. A draft isn't visible to the customer
3. Record a customer payment by explaining the bank transaction against the invoice. There's no invoice payments endpoint
4. Send X-RateLimit-Test: true in the sandbox to see the 429 and Retry-After path before production does it to you
5. Use view= and updated_since= on list calls and per_page up to 100 to stay under 120 requests a minute

### Zoho Books

1. Send `organization_id` as a query parameter on every call. Read it from `GET /organizations` first
2. Use the `api_domain` returned with the token, since each of the nine data centres has its own host (zohoapis.com, zohoapis.eu, zohoapis.in and others)
3. Send `Authorization: Zoho-oauthtoken <token>` and refresh hourly. Each user keeps at most 20 refresh tokens and the oldest is deleted
4. Stay under 100 requests a minute and the plan's daily cap. Codes 44, 45 and 1070 on a 429 mean minute, day and concurrency limits
5. To repeat an update safely, send `X-Unique-Identifier-Key`, `X-Unique-Identifier-Value` and `X-Upsert` with a unique custom field. Creates have no idempotency key

## Questions

### Which is better for AI agents, FreeAgent API or Zoho Books?

Zoho Books scores 61.1 (C) on agent readiness against FreeAgent API's 57.2 (C), and leads in 3 of 7 scored categories. FreeAgent API leads on reliability.

### Do FreeAgent API and Zoho Books need an API key?

Both use an OAuth sign-in.

### Can an agent call FreeAgent API and Zoho Books without installing anything?

Yes. FreeAgent API has a hosted endpoint at https://api.freeagent.com/v2 and Zoho Books at https://www.zohoapis.com/books/v3.


## For agents

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

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