# Companies House XML Gateway – “XML failed schema validation line 16 column 155” on IN01 v3.8 submission (GovTalkMessage Body issue) **URL:** \ **Category:** Incorporation\ **Created:** [December 4, 2025, 1:59pm UTC](https://xmlforum.companieshouse.gov.uk/t/companies-house-xml-gateway-xml-failed-schema-validation-line-16-column-155-on-in01-v3-8-submission-govtalkmessage-body-issue/1888 "2025-12-04T13:59:42Z")\ **Posts on this page:** 4\ **Page:** 1

**Author:** ![MrHamza](https://xmlforum.companieshouse.gov.uk/letter_avatar_proxy/v4/letter/m/5daacb/32.png) [@MrHamza](https://xmlforum.companieshouse.gov.uk/u/MrHamza)\ **Post date:** [December 4, 2025, 1:59pm UTC](https://xmlforum.companieshouse.gov.uk/t/companies-house-xml-gateway-xml-failed-schema-validation-line-16-column-155-on-in01-v3-8-submission-govtalkmessage-body-issue/1888/1 "2025-12-04T13:59:42Z")

Hello everyone, I’m integrating with the Companies House XML Gateway for submitting IN01 company incorporations using the new **CompanyIncorporation-v3-8** schema. I have a test Presenter ID and Authentication Value directly from Companies House staff (Simon), and I’m posting to the correct endpoint: ```auto https://xmlgw.companieshouse.gov.uk/v1-0/xmlgw/Gateway ``` ### ✔ What is working: - The request hits the gateway. - The `` and `` are correctly formatted as `md5#`. - `` is set to `clear` as required. ### ❗ The issue: No matter what I try, I ALWAYS get the same error: ```auto Error 100: XML failed schema validation: XML error: Fatal error encountered during schema scan line 16 column 155 ``` This happens even though: - The GovTalkMessage root includes **only one** schemaLocation (Egov\_ch.xsd) - `` contains only `` - `` uses exactly: `xmlns="http://xmlgw.companieshouse.gov.uk/Header"` - No prefix is used (no ch-header). - CompanyIncorporation no longer contains any schemaLocation. ### ✔ Here is the exact XML I am sending (redacted): ```auto 1.0

CompanyIncorporation request ED847AA1E8A047738BF019D2527968F3 md5#d75d15c712c7f01739eafb9c0b5a1e18 clear md5#e04dc725dc513f0979fef06afa2dddb1

Test Ltd 0012 CompanyIncorporation 000004 2025-11-28 ``` ### ❗ Expected behavior: I expected the gateway to accept the XML or at least show a schema **path** of the validation failure. ### ❗ Actual behavior: The gateway responds with: ```auto CHMD5 Error 100 Fatal error encountered during schema scan line 16 column 155 ``` ### ✔ What Simon from CH already confirmed: - Endpoint is correct - Must use `md5#` format - `` must be `clear` - Do NOT combine hashes (no PresenterID + AuthValue + SubmissionNumber) - IN01 must use **v3.8** - `FormSubmission` must use _only_ `xmlns="http://xmlgw.companieshouse.gov.uk/Header"` ### ❓ What I need help with: Can anyone confirm **the exact required XML structure** for: - `` - `` - `

` - `` nesting - Namespace expectations between Header and Body - Any common hidden mistakes that cause a failure at “line 16 column 155”? (that line corresponds to ``) If someone has a working example (even simplified), that would be extremely helpful. Thanks! ---

**Author:** ![ashwakeman](https://xmlforum.companieshouse.gov.uk/letter_avatar_proxy/v4/letter/a/dbc845/32.png) [@ashwakeman](https://xmlforum.companieshouse.gov.uk/u/ashwakeman)\ **Post date:** [December 4, 2025, 2:58pm UTC](https://xmlforum.companieshouse.gov.uk/t/companies-house-xml-gateway-xml-failed-schema-validation-line-16-column-155-on-in01-v3-8-submission-govtalkmessage-body-issue/1888/2 "2025-12-04T14:58:39Z")

Redacted header we send, including additional HMRC info (which I believe is optional). Have cut it off once it starts getting into the company details. Haven’t given yours a once over or compaed it yet, but will have a snoop now. ```auto 1.0

CompanyIncorporation request 12345 XXX clear YYY inc@ourdomain.com

REDACTED IMITED 1234 CompanyIncorporation aaa000 2025-12-12 2025-12-12 2026-12-12 false ADDRESS BLOCK BYSHR EW etc etc ``` Feel I should add that while I know a fair bit about incorporation specific XML I am not an expert on XML in general and don’t really know how all the schema statments in headers work in general so some of these were trial and error back in the day or may be completely redundant. Also in your example above you’re missing the document block between and but I don’t know if that’s an artifact of refacting (redaction?) ```auto xxx 2025-12-03 application/pdf ARTS ``` ---

**Author:** ![snicholas](https://xmlforum.companieshouse.gov.uk/user_avatar/xmlforum.companieshouse.gov.uk/snicholas/32/81_2.png) [@snicholas](https://xmlforum.companieshouse.gov.uk/u/snicholas)\ **Post date:** [December 8, 2025, 1:49pm UTC](https://xmlforum.companieshouse.gov.uk/t/companies-house-xml-gateway-xml-failed-schema-validation-line-16-column-155-on-in01-v3-8-submission-govtalkmessage-body-issue/1888/3 "2025-12-08T13:49:17Z")

Hi, Is there any reason why you have md5# typed in these elements please? md5#d75d15c712c7f01739eafb9c0b5a1e18 clear md5#e04dc725dc513f0979fef06afa2dddb1 You just the need the md5# values, not the term itself. SDN ---

**Author:** ![user67](https://xmlforum.companieshouse.gov.uk/user_avatar/xmlforum.companieshouse.gov.uk/user67/32/210_2.png) [@user67](https://xmlforum.companieshouse.gov.uk/u/user67)\ **Post date:** [February 12, 2026, 5:04pm UTC](https://xmlforum.companieshouse.gov.uk/t/companies-house-xml-gateway-xml-failed-schema-validation-line-16-column-155-on-in01-v3-8-submission-govtalkmessage-body-issue/1888/4 "2026-02-12T17:04:00Z")

Hi There Have you solve your issue ?