Applying to Sigma AI · researched 5 Nov 2026

How to apply to Sigma AI

Find the project for your language on careers.sigma.ai, click Apply for this job, complete the mandatory tests Sigma emails you (check spam), provide any identity and credential documents it asks for, then sign a freelance commercial contract and work remotely on Sigma's online platform; Sigma publishes no pay rate or payment terms, so ask for them before you start.

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Applying to Sigma AI, step by step

Researched Nov 2026

Who can join

Native or fluent command of the project's language, able to listen and write without spelling mistakes. Most remote projects also ask for fluent English and basic computer skills. Experience is preferred but not required: on 5 November 2026 the Cantonese post and 18 other posts on Sigma's careers feed name computational linguistics, corpus analysis, language data annotation or LLM training, and 61 posts name data annotation or content rating.
For translator roles, more: the Romanian Translator post asks for a Bachelor's degree in Translation and Interpretation, native or near-native Romanian, fluent English and a solid command of linguistic theory and grammar.
A computer with at least 4GB of RAM, a microphone and webcam, Windows 10 or macOS 13 Ventura or later with all updates, a stable internet connection, headphones and a secure, password-protected internet location. Audio-collection projects also need an Android phone; tablets and iOS devices are not supported.
Documents that prove your identity and credentials. Every post says the candidate agrees to provide them on request, and that Sigma may withhold or terminate an offer if the evidence is not enough.
Willingness to work as a freelancer: remote projects are offered under a commercial contract, not employment.
For some projects, being in London or Madrid: on 5 November 2026, 15 of the 88 posts on Sigma's careers feed were on-site in London and 1 (Italian) in Madrid, and they ask for English (in Madrid, English or Spanish) good enough to work in an office.

Step by step

1
Find the post for your language
Sigma recruits per language and per variety, not through one general sign-up. On 5 November 2026 its careers feed held 88 posts: 72 remote, 15 on-site in London and 1 on-site in Madrid. The newest were a remote Czech and English post (4 November), on-site London posts for Serbian and Slovak (30 October) and Swedish (27 October), and a remote Cantonese post (19 October).
2
Check the requirements and your equipment
Read the language, skills and technical requirements in the post before you apply. Audio-collection work needs an Android phone or a Windows computer; tablets and iOS devices are not supported.
3
Apply on careers.sigma.ai
Click 'Apply for this job' and follow the instructions. Apply directly: Sigma says it does not hire through third parties, and no agents or intermediaries are authorized to take part in the relationship.
4
Complete the emailed tests
After you apply, Sigma emails you the required tests, which are mandatory to move forward; check your spam folder too. Sigma says it may use AI systems to evaluate the tests, for instance the transcribed content you submit.
5
Send identity and credential documents if asked
Sigma can ask for any documentation it reasonably needs to verify who you are and your credentials, and may withhold or end an offer without it.
6
Read and sign the freelance contract
Remote work is offered to freelancers under a commercial contract. One December 2025 Trustpilot reviewer says her contract came through Sigma's US office with one-sided clauses and urges legal advice before signing, so read it closely and ask about the rate and payment terms first.
7
Start work on Sigma's platform
All tasks are remote, on an online platform available 24/7. Some projects are short: the French voice-command audio project asks for 500 short utterances over two recording sessions, about 2.5 hours in all, with project manuals and optional kick-off sessions.

Language tests emailed after you apply

Every remote post says that after you apply you receive an email with the required tests, and that they are mandatory to move forward. Sigma says it may use AI systems to evaluate them, for instance the transcribed content you provide. Sigma does not publish what the tests contain, how long they take, the pass mark or whether they are paid; applicants on Trustpilot describe transcribing test audio clips and, for some roles, a translation test.

Format

Emailed tests in the project's language. Applicant reports describe audio transcription (one says five audio files, about 35 minutes in all) and, for translator roles, a translation test with its own guideline.

How to prepare

Check your inbox and spam folder right after applying: the tests arrive by email.
Transcribe exactly what you hear and spell everything correctly. Every post asks for people able to listen and write without spelling mistakes.
Use headphones in a quiet place on a computer that meets the post's requirements (4GB of RAM, microphone, updated Windows 10 or macOS 13).
Read the test guidelines in full before you start, and ask questions early: one applicant said a translation guideline was confusing and his email asking for clarification went unanswered.
Have your ID and any degree certificate ready, since Sigma may ask for proof of identity and credentials.

Why people get rejected

Spelling mistakes or an inaccurate transcription, the one skill every post insists on.
Not completing the mandatory tests, or missing the email in a spam folder.
Not giving enough evidence of identity or credentials: Sigma says it may then withhold or terminate an offer.
Equipment that does not qualify, such as an iPhone or a tablet for an audio-collection project.

How long it takes

Sigma publishes no timeline from application to first paid work, and no step tells you when you have been turned down. Some applicants on Trustpilot say they finished the tests and never heard back. Projects also differ widely in size, so being accepted onto one may not mean ongoing work.

When you get paid

Sigma does not publish how or when freelancers are paid. Its posts offer remote work to freelancers under a commercial contract, and none of the 88 posts on its careers feed on 5 November 2026 stated a rate. Ask for the rate, its unit (per hour, per audio minute or per task), the payment method and the schedule in writing before you start.

Tips to get accepted

Apply only through careers.sigma.ai. Sigma says it does not hire through third parties, so anyone offering Sigma work through an agency, a fee or a chat app is not Sigma.
Apply to every post that matches your languages. Sigma recruits per language and variety, and combinations such as Korean and Chinese, Korean and Japanese, or German, Russian and English have their own posts.
Ask for the rate before you put hours into tests or work. Reviewers describe transcription paid per minute of audio, unpaid meetings and tests, and one says his wife had not been paid for about 80 hours over two weeks.
Read the freelance contract before signing and question anything one-sided; one reviewer recommends getting legal advice first.
Keep an Android phone available if you want audio-collection projects: they do not support iOS devices or tablets.
Use the project manuals and optional kick-off sessions that audio projects offer to clear up technical or procedural questions before you record.

What isn't public

Sigma publishes no pay rates: none of its 88 posts on 5 November 2026 stated one. It also publishes no payment method, schedule, currency or minimum for freelancers.
It does not say what its tests contain, how long they take, how they are scored or whether they are paid; Trustpilot reviewers describe them as unpaid.
There is no published timeline and no stated way you are told you were not selected; some applicants say they never heard back after the tests.
Which Sigma company signs your contract (Spain, the UK or the US) is not stated in the posts; one reviewer says hers came from the US office.
Sigma's own figures disagree (read 5 November 2026): its FAQ and About page say it was founded in 2008 and covers 500+ languages (About: 25,000+ annotators), its homepage says 18+ years, 700+ languages and 70,000+ experts, its careers site more than 2,500 people, and its job posts claim over 30 years of experience and 200+ or 700+ languages.
The 15 on-site London posts and the on-site Madrid post do not say whether they are freelance or employment, and do not describe the remote tests; the careers feed's job data on 5 November 2026 labels those 16 posts full-time and the 72 remote posts temporary.
Public worker reviews are few: on 29 October 2026 Trustpilot had 7 reviews of sigma.ai and 8 of sigma-ai.com (a domain that redirects to sigma.ai, listed as Sigma Technologies, all 1-star), and Glassdoor refused a plain fetch, so it is not used here.

Sources (11)

Sigma AI Careers: job feed (88 posts, read November 5, 2026)
Sigma AI Careers: Cantonese Chinese (Traditional script) Linguistic Projects (Remote), posted October 19, 2026
Sigma AI Careers: Romanian Translator (Remote)
Sigma AI Careers: French Audio Collection Projects (Remote)
Sigma AI Careers (Madrid, London and Miami, more than 2,500 people; read November 5, 2026)
Sigma AI: FAQs (founded 2008 in Madrid, offices, 500+ languages; read November 5, 2026)
Sigma AI: About
Sigma AI: homepage
Trustpilot: sigma.ai reviews, all languages
Trustpilot: sigma-ai.com reviews (profile named Sigma Technologies)
sigma-ai.com (redirects to sigma.ai, checked November 5, 2026)

Applying to Sigma AI: questions

How do I get accepted on Sigma AI?

Apply to the post for your language on careers.sigma.ai, complete the mandatory tests Sigma emails you, and provide any identity and credential documents it asks for. Remote work is then offered to freelancers under a commercial contract.

Does Sigma AI have a test?

Yes. After you apply, Sigma emails you the required tests, which are mandatory, and says it may use AI to evaluate them, for instance your transcribed content. It does not publish their length, pass mark or whether they are paid.

How much does Sigma AI pay?

Sigma does not say. None of the 88 posts on its careers feed on 5 November 2026 stated a rate, so ask for the rate and its unit (per hour, per audio minute or per task) in writing before you start.

How does Sigma AI pay its freelancers?

Sigma publishes no payment method or schedule. Trustpilot reviewers describe transcription paid per minute of audio; one says payments are regular, while others describe unpaid tests, unpaid meetings and unpaid hours.

Can I work for Sigma AI from home?

Yes, for most projects. On 5 November 2026, 72 of the 88 posts on its careers feed were remote, 15 were on-site in London and 1 was on-site in Madrid.

What equipment do I need for Sigma AI?

A computer with at least 4GB of RAM, a microphone and webcam, Windows 10 or macOS 13 Ventura or later, headphones and stable internet. Audio-collection projects also need an Android phone; tablets and iOS devices are not supported.

Do I need a degree to work for Sigma AI?

Not for most linguistic projects, which ask for fluency, correct spelling and basic computer skills. Translator roles are stricter: the Romanian Translator post asks for a Bachelor's degree in Translation and Interpretation.

How long does it take to hear back from Sigma AI?

Does Sigma AI have an assessment?

Yes: Language tests emailed after you apply. Every remote post says that after you apply you receive an email with the required tests, and that they are mandatory to move forward. Sigma says it may use AI systems to evaluate them, for instance the transcribed content you provide. Sigma does not publish what the tests contain, how long they take, the pass mark or whether they are paid; applicants on Trustpilot describe transcribing test audio clips and, for some roles, a translation test.