SEIS Services Companies in the UK: Firms Guide (2026)
AC
Acumon Chartered Accountants·13 min read
For founders preparing to raise seed capital, SEIS support can cover much more than submitting an HMRC form. Depending on the provider, services may include eligibility checks, advance assurance, share issue guidance, compliance statements and investor certificates. This guide looks at a selection of SEIS services companies in the UK rather than treating the list as a ranking.
Acumon
Acumon is a UK firm of chartered accountants and registered auditors providing SEIS and EIS support to companies looking to raise investment. Its services cover key parts of the process, including reviewing eligibility, considering how an investment should be structured, preparing for Advance Assurance and supporting ongoing compliance requirements.
The firm’s wider experience in tax, accounting and corporate advisory work can be useful when an SEIS raise needs to fit into a company’s broader financial plans. Early-stage and growing businesses often need to consider not only whether they qualify for SEIS, but also how a proposed share issue and investment structure may affect their tax and reporting position.
Acumon holds a Public Interest Entity (PIE) audit licence, allowing the firm to audit listed companies and other entities subject to enhanced regulatory oversight in the United Kingdom. PIE audits are subject to additional regulatory supervision and quality requirements, and only a limited number of firms are authorised to undertake this type of work.
In addition to its UK audit registration, Acumon also holds audit licences in several international financial centres, including the Cayman Islands, British Virgin Islands (BVI), Jersey, and Isle of Man. These licences enable the firm to support international corporate groups where entities are located across multiple jurisdictions.
Acumon works with founders and management teams throughout the SEIS process, helping them understand the relevant requirements and deal with the associated HMRC procedures. SEIS advice is integrated with the company’s wider accounting, tax and financial reporting requirements rather than handled as a separate process.
SEIS Service Capabilities
Acumon provides external SEIS Services across a wide range of organisational structures and sectors.
These include:
UK limited companies and corporate groups
Public Interest Entities (PIEs) and regulated organisations
offshore holding companies and investment vehicles
SEIS engagements are typically led by senior professionals with direct involvement throughout.
Regulatory Licences and Registrations
Acumon holds several audit registrations that enable it to support organisations operating across multiple jurisdictions.
These include:
UK statutory audit registration
Public Interest Entity (PIE) audit licence
Jersey audit licence
Isle of Man audit licence
Cayman Islands audit licence
British Virgin Islands audit licence
These registrations allow the firm to provide audit services to groups that include entities in both the UK and key international financial centres.
Core Services
In addition to seis services, Acumon provides a range of services that support financial reporting and governance.
These include:
statutory external audit
group and subsidiary audits
Public Interest Entity (PIE) audits
charity and not-for-profit audit
audit of international group structures
internal audit and governance reviews
risk management and compliance support
Audit work is often delivered alongside discussions with management and boards regarding financial reporting processes and governance frameworks.
Many organisations initially encounter statutory audit requirements as they grow and exceed the audit exemption thresholds set out in the Companies Act.
Acumon works with businesses that are:
approaching their first statutory audit
preparing for external investment
expanding into international markets
operating within corporate group structures
Early engagement with an audit firm can help ensure that financial reporting systems and documentation are aligned with statutory audit requirements.
Address: 1-2 Craven Road, Ealing, London, W5 2UA, UK
Perrys Chartered Accountants
Perrys Chartered Accountants advises both businesses and investors on the Enterprise Investment Scheme and Seed Enterprise Investment Scheme. For companies, its work focuses on understanding the scheme requirements and using SEIS or EIS as part of an external investment round.
The firm also approaches the schemes from the investor side, providing guidance around available reliefs and investment-related tax considerations. This makes Perrys relevant where founders and individual investors both need professional accountancy and tax input around a transaction.
Key Facts
Ideal for: Businesses raising outside investment and individuals considering SEIS investments
Core services: SEIS and EIS advice, investor tax guidance, business tax advice Specialization: Chartered accountancy and tax
Notable strength: Services cover both company and investor considerations
Address: 4th Floor, 399-401 Strand, London, WC2R 0LT, UK
Phone: 020 7408 4442
SeedLegals
SeedLegals takes a platform-based approach to SEIS and EIS work. UK startups can use its workflow to prepare an Advance Assurance application, have the information reviewed and submit the application to HMRC. The process covers company details, prospective investor information and supporting documents such as the business plan or pitch deck.
Its services extend beyond Advance Assurance to post-funding SEIS and EIS compliance. SeedLegals can therefore suit founders who want SEIS paperwork connected with their funding round, share issuance, cap table and other startup legal documentation rather than handled as a standalone tax engagement.
Key Facts
Ideal for: Startups managing SEIS alongside a funding round
PKF Francis Clark has a dedicated EIS and SEIS tax advisory service for companies and investors. Its specialists can assess whether a company has a reasonable prospect of qualifying, advise on steps needed to meet the requirements and assist with an HMRC Advance Assurance application before a funding round.
Support continues after the investment. The firm can assist with SEIS1 and EIS1 applications and the corresponding investor documentation, while also advising companies on actions that could affect qualification during the relevant holding period. PKF Francis Clark is also a member of the Enterprise Investment Scheme Association.
Key Facts
Ideal for: Companies requiring tax-led SEIS support through several stages of a funding round
Core services: Eligibility advice, Advance Assurance, SEIS1/EIS1 applications, SEIS3/EIS3 support
Specialization: Tax advisory and business services
Notable strength: Advice extends from initial qualification through post-investment requirements
Address: Centenary House, Peninsula Park, Rydon Lane, Exeter, Devon, EX2 7XE, UK
Phone: 01392667000
Fusion Accountants
Fusion Accountants provides a dedicated SEIS and EIS accounting service aimed largely at startups raising capital. Its support covers the investment scheme process alongside areas such as business structure, business plans, tax and accounting.
For founders, the firm can provide guidance on eligibility and the paperwork involved in an SEIS or EIS application. Because Fusion also handles regular startup accounting, bookkeeping, payroll, VAT and statutory accounts, companies can keep investment scheme work within the same accounting relationship used for their routine financial obligations.
Key Facts
Ideal for: Startups wanting SEIS support from their wider accounting provider
Core services: SEIS and EIS support, tax advisory, accounting, business structure guidance
Specialization: Startup and SME accounting
Location: London and surrounding areas
Notable strength: Combines SEIS work with ongoing startup accounting
Address: Profile West, Suite 2, Floor 1, 950 Great West Road, Brentford, TW8 9ES, UK
Phone: 020 8577 0200
BDO UK
BDO provides venture capital tax relief advice covering SEIS, EIS and VCT arrangements. For companies considering an SEIS raise, its services include guidance on qualifying conditions, HMRC Advance Assurance and the compliance process after shares have been issued.
Its work can also involve reviewing articles, shareholder agreements and investment agreements to identify issues that could affect the availability of relief. The firm’s published SEIS guidance addresses qualifying companies, share requirements, Advance Assurance and the SEIS1 and SEIS3 process, making its service particularly relevant where the investment sits within a wider corporate tax matter.
Key Facts
Ideal for: Companies with broader corporate tax or transaction requirements around an SEIS raise
Core services: SEIS advice, Advance Assurance, compliance statements, document review
Specialization: Corporate tax and venture capital tax relief
Industries: Published examples include technology, leisure, media and retail
Notable strength: SEIS advice can be coordinated with broader corporate tax services
Contact Information
Website: www.bdo.co.uk
LinkedIn: www.linkedin.com/company/bdo-llp
Instagram: www.instagram.com/lifeatbdo
Address: 55 Baker Street, London, W1U 7EU, United Kingdom
Phone: 020 7486 5888
Metric Accountants
Metric Accountants offers a dedicated SEIS tax relief service for startups looking to raise capital. Its process begins with Advance Assurance, followed by support around the legal and administrative steps required when new shares are issued.
The service is structured around the different stages a company encounters rather than treating SEIS as a single application. This can be useful for first-time founders who need help understanding how HMRC Advance Assurance, company approvals and the eventual share issue connect to one another.
Key Facts
Ideal for: Early-stage businesses preparing their first SEIS share issue
Core services: SEIS Advance Assurance, share issue support, SEIS tax guidance
Specialization: Accounting and tax services for growing businesses
Notable strength: Step-by-step support around the company side of an SEIS raise
Contact Information
Website: www.metricaccountants.co.uk
SEIS Accountants
SEIS Accountants is a specialist service delivered by Tidy Money Ltd, an ACCA-regulated practice. Unlike broader accountancy firms where SEIS may be one part of a large tax department, this service concentrates on the SEIS and EIS lifecycle for UK founders.
Its work includes Advance Assurance, share issuance and cap table support, SEIS1 and EIS1 compliance statements, investor certificates and monitoring during the qualifying period. This narrower focus can suit founders who specifically want scheme administration and ongoing eligibility support rather than a broad corporate advisory engagement.
Key Facts
Ideal for: Founders seeking specialist SEIS and EIS administration
Alliotts provides EIS and SEIS advice as part of its wider business and private client tax services. Its published material confirms that the firm advises companies on scheme eligibility and can assist with applications.
The wider practice covers corporate tax, business advice, valuations, international tax and corporate finance. That breadth can matter when an SEIS investment forms one element of a larger business plan, particularly where share structures, future funding or international considerations also need professional input.
Key Facts
Ideal for: Businesses combining SEIS with wider tax and business advice
Core services: EIS and SEIS eligibility advice, application assistance, tax planning
Specialization: Chartered accountancy, tax and business advisory
Notable strength: Access to wider corporate finance and tax capabilities
Address: Manfield House, 1 Southampton Street, London, WC2R 0LR, UK
Phone: +44 (0)20 7240 9971
Seisly
Seisly is built specifically around the fundraising workflow for SEIS and EIS companies. Its Advance Assurance service can cover application preparation, expert review and submission to HMRC, while its broader workspace is designed to keep company information and fundraising documentation together.
The service also includes SEIS1 and SEIS3 compliance functionality. This gives Seisly a different profile from a conventional accounting firm: it is geared toward founders who prefer a digital workspace and focused fundraising tools, with specialist review available as part of the application process.
Key Facts
Ideal for: Founders wanting a digital SEIS fundraising workflow
Address: 71-75 Shelton Street, Covent Garden, London WC2H 9JQ, UK
Zmartly
Zmartly provides SEIS and EIS accounting services for UK startups and SMEs. Its scope covers eligibility checks, Advance Assurance applications, share issues, SEIS1 and EIS1 compliance statements and the SEIS3 or EIS3 certificates investors need for their tax claims.
The firm also provides ongoing accounting services, so the SEIS process can be connected with bookkeeping, company accounts and tax work. Its scheme service includes reviewing qualifying-company conditions before a raise and continuing with compliance once the shares have been issued.
Key Facts
Ideal for: Startups seeking SEIS support alongside ongoing accounting
Northrow SEIS & EIS has a deliberately narrow service model focused on Advance Assurance for early-stage UK companies. Its work begins with an eligibility assessment and review of the company’s trade and growth plans before moving into preparation of the HMRC narrative and supporting documentation.
The service also covers submission of the Advance Assurance application, communication with HMRC and guidance around share classes and investor communications. This focused scope may suit founders who already have accountants and other advisers but want dedicated help with the Advance Assurance stage of their raise.
Key Facts
Ideal for: Companies primarily needing specialist Advance Assurance support
Notable strength: Narrow focus on the pre-investment assurance process
Contact Information
Website: northrowseis.co.uk
Startup Accountants UK
Startup Accountants UK provides SEIS and EIS advice specifically in the context of early-stage businesses. Its service covers qualifying tests, Advance Assurance and the compliance work required after an investment round.
The firm’s SEIS materials also address mixed SEIS and EIS rounds, share issuance and investor certificates. This startup-focused approach can be relevant for founders who need scheme guidance tied closely to the practical sequence of fundraising, rather than SEIS advice delivered separately from their day-to-day startup accounting.
Key Facts
Ideal for: Early-stage companies preparing SEIS or combined SEIS/EIS rounds
AdvanceAssured offers a software-led route to preparing an SEIS or EIS Advance Assurance application. Rather than providing a full accounting relationship, the service is focused on helping founders produce the information and documents required for an HMRC-ready application.
This narrower model makes it different from firms that combine SEIS with accounts, corporation tax and ongoing advisory work. It may be more relevant to straightforward cases where founders already have their wider professional support in place and mainly need assistance preparing Advance Assurance documentation.
Key Facts
Ideal for: Founders looking for a focused, software-based Advance Assurance process
Core services: SEIS/EIS eligibility checking and Advance Assurance application preparation
Specialization: SEIS and EIS Advance Assurance
Notable strength: Dedicated digital workflow rather than a wider accounting engagement
Contact Information
Website: www.advanceassured.co.uk
SEIS Advance Assurance
SEIS Advance Assurance is another specialist service built around obtaining Advance Assurance for companies preparing SEIS or EIS investment rounds. Its offering centres on helping businesses complete the application rather than providing the full range of services normally associated with a general accountancy practice.
The service includes access to an SEIS and EIS specialist and positions the Advance Assurance application as a defined standalone engagement. This can suit founders whose existing accountant handles routine financial work but who want separate assistance with this particular part of an investment round.
Key Facts
Ideal for: Founders needing standalone Advance Assurance application support
Core services: SEIS and EIS Advance Assurance assistance
Notable strength: Focused service for the pre-investment application stage
Contact Information
Website: seisadvanceassurance.co.uk
Address: 6 Yorkton St, London E2 8NH, United Kingdom
Conclusion
SEIS service providers in the UK vary considerably in how much of the funding process they handle. Some focus mainly on Advance Assurance, while others stay involved through eligibility reviews, share issuance, SEIS1 compliance and investor certificates. Full-service accountancy firms can also connect the scheme with corporation tax, financial reporting and longer-term business advice.
There is no single provider that fits every SEIS raise. A startup with an established accountant may only need specialist Advance Assurance support, while a first-time founder may prefer a provider that can manage the process from initial eligibility through post-investment compliance. The right choice depends on the complexity of the company, the stage of the raise, the support already in place and how much ongoing involvement is required.
AC
Written by the Acumon team
Acumon is an ICAEW-registered firm of chartered accountants and registered auditors
based in London, with offices in Pitstone, Aylesbury and Bournemouth. Need advice on
anything covered here? Talk to us.
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