How to build your Advance Assurance application with SeedLegals
A step-by-step guide to securing S-EIS tax relief for your investors
What is SEIS / EIS Advance Assurance?
If your startup is incorporated in the UK, you have likely heard of SEIS (Seed Enterprise Investment Scheme) and EIS (Enterprise Investment Scheme). These government-backed schemes provide significant tax breaks to investors, making your company a far more attractive prospect for funding.
Funding via these schemes is at an all-time high. The latest official HMRC statistics for the 2023 to 2024 tax year (released in May 2025) show:
- SEIS: 2,290 companies raised a total of £242 million—a massive 51% increase in funding compared to the previous year. This growth was fueled by the expansion of the scheme limits in 2023.
- EIS: 3,780 companies raised a total of £1,575 million. While the broader economy has been challenging, EIS remains the cornerstone of the UK’s venture capital ecosystem.
The takeaway: Investors are actively looking for companies that offer these tax reliefs. If you can prove your eligibility, you significantly increase your odds of landing a deal.
Why Advance Assurance is Essential
Advance Assurance is a formal confirmation from HMRC that a future investment in your company is likely to qualify for tax relief.
- The 90% Rule: Approximately 90% of UK angel investors will not commit funds until they see your Advance Assurance. It is often the very first document they request.
- Timing: HMRC typically takes 15 to 45 working days to process applications. We recommend starting your application at least two months before you plan to start your round to avoid delays.
Applying for SEIS / EIS Advance Assurance with SeedLegals - the easy way
Applying for Advance Assurance can be quite complex to do on your own. The good news is that applying with SeedLegals is easy, quick and efficient. It shouldn’t take you more than 15-30 minutes to complete your application on SeedLegals.
Then, you’ll send us your application for review, and our dedicated S-EIS team will get back to you in 3-5 business days with our review, which includes all our comments before it can be submitted to HMRC. Our goal is to get you approved, so we will work closely with you to flag any issues in your application and to help you correct them.
With Advance assurances, we have a 98% success rate with HMRC! Just to compare, HMRC released stats last year showing that the general success rate is only 62%.
Once you get our “green light” (i.e. after we feel comfortable that your application is in the best shape possible, and you’ve corrected all the issues we flagged), we will submit your application to HMRC directly. Within 15 to 45 working days, HMRC should get back with an approval, which your dedicated associate will promptly communicate to you!
Do I need to speak with anyone to get started?
No. You can start building your application on the SeedLegals platform whenever and wherever you like. If you have any questions along the way, you can always use the chat feature on the platform, and our support team will reply to you in minutes!
You will need a membership, on top of the Advance Assurance fee.
If you're a new customer, you can book a call with our team here:
https://seedlegals.com/talk-to-an-expert/
Otherwise, you can reach out to your account manager and they will set you up!
The Step-by-Step Guide to Your Application
Starting out
After logging into the platform, you’ll see this dashboard. Hit ‘Raise’ > and then the "Create" button:

Then, select "Advance assurance" on the next page: 
A new window will open on the right side of the screen. Just click on the ‘Start now’ button.
Next, you'll need to click the 'unlock' button.

1. Complete the questions
The first section requires you to fill out information regarding your company details.
Your company will need to be incorporated and have a Unique Taxpayer Reference Number 'UTR'. We can review your application even if you don't have your UTR yet, but note that you will need it before we can submit the application to HMRC.
On the next page you will be asked whether you’ve received any past SEIS, EIS or state aid investments. State aid includes de minimis aid, e.g. a government grant, and previous investment doesn't include money that the founders put into the business or non-SEIS/EIS investment. Please note, any eligible previous investments will be deducted from your total S/EIS allowance.

On the following page, select which scheme you're applying for. If you're applying for up to £250k then only select SEIS. If you are applying for anything higher, then you should select both SEIS and EIS (you can apply for both at the same time) - unless your company is not eligible for SEIS at this stage. If you’re not sure about your eligibility, have a read of this article.
If you’re raising EIS, you’ll also need to specify whether you’ve made a commercial sale, or are applying as a Knowledge Intensive Company (KIC)


We recommend leaving our suggested wording in place in response to the question of “why are you a growth company that meets the risk-to-capital condition”, and demonstrating how you meet the condition within your pitch deck using a SWOT analysis.
HMRC asks this question because they try to avoid artificial investments that are done just for the sake of getting S/EIS tax relief without taking on any risk. Genuinely entrepreneurial start-ups should not be affected by this provision. We suggest you use our default wording: “The risk to capital requirement has been met, see our attached Business Plan for details”.
Following this, you need to tell HMRC what “qualifying business activity” the funds will be used for. If you will use the money from your investment to begin your trade, please select 'Trade'. If, however, you intend to spend the funds solely on R&D that will lead to the trade in the future, please select 'R&D intended to lead to a qualifying purpose'. Finally, if you are already trading but want to spend the funds on R&D for further development, please select ‘R&D for an existing qualifying trade’.

Regardless of whether you select Trade, R&D or R&D for an existing trade, you'll then need to select whether the trade/R&D has started yet. If yes, then you'll also need to include the date when you started trading/R&D as well as the relevant details. If not, you'll simply need to fill in the details of the trade/R&D.
Additionally, companies that select 1 of 2 R&D options will need to answer the question “How do your company activities qualify as R&D for tax purposes?”. We recommend leaving out default wording “The R&D activities are detailed in a separate cover letter” and uploading an R&D plan to the platform. Guidance will be provided from your advance assurance reviewer once submitted to SeedLegals for review.

HMRC also wants to understand your trading activities. Here you can choose one of two tactics, either explain in detail your activity (making sure it’s consistent with your pitch deck) or just refer HMRC to the attached business plan. We recommend leaving the suggested text as it is for the application. The business plan is part of your application - no worries, you’ll get a list from us later of all the documents that need to accompany your application.

Following the above, you will see this next question below (a variation of this question will appear if you select R&D as well). Please answer this honestly, as it will help determine whether you need to include an brief cover letter explaining your company's past trading activities.

If you have received SEIS or EIS investment in the past, you will not need to provide details of your investors. However, if you have not, you will need to present a list of your potential investors to HMRC. For angel investors, you will need their full legal name and address, and for all other options, you will need to provide a letter of engagement. For raises up to £500k, you need to put down at least one potential investor that covers 25% of the overall amount you are applying for. For raises over £500k, the proposed investment should cover at least 50%.
The next page covers 'Assets and employees'. You'll need to put the value of your company’s assets. Keep in mind that HMRC will only approve SEIS applications with gross assets of less than £350K (and less than £15 Million for EIS).

For the employee question, put a number here only if the employees are on the company’s payroll. In cases where you have part-time employees, combine their part-time roles into whole numbers. For example, two half-time employees would be equal to one full-time employee (most of the companies applying for the Advance Assurance are early-stage companies, so it’s very common not to have employees at this point). However, company directors also count as employees for the purpose of this test - you can see more about this here. Therefore, the number of employees should never be "0" as all companies have at least one director!

The next page covers details about your upcoming round. If individuals are investing in your company, please select ‘angel investors’. Only select ‘SEIS/EIS funds’ or the other options if a VC fund or crowdfunding platform is funding you, and choose the last option if you are engaging an advisor to find investors.

Next, simply set the total number of your next funding round. For example, if you’re about to do a funding round of £350,000, that’s the number you should put in this text box. Please note that this should only be the SEIS or EIS amount you are raising. If you are raising additional non-S/EIS funds, you do not need to include this in your overall amount.

Here, you'll need to tell HMRC what the funds will be used for. We recommend just selecting some of our prepared options which we know to be HMRC friendly, but feel free to add any additional ones (your reviewer will check whether your intended uses of funds are likely to be eligible, and send you notes on this in their review).

For the following question, select ‘yes’ only if you’ve got a term sheet or shareholders agreement from your investors. But if you haven’t or if you don’t have investors yet, hit ‘no’. Not to worry, it won’t affect your chances of getting approved by HMRC (most of the companies don’t have a Term Sheet or else at this point).

When you registered your company at Companies House, the Model Articles were applied by default. So if you have not changed them, just choose ‘no’ (most companies are still using the Model Articles at this point).

In the following section (which only appears for EIS applications), HMRC wants to understand whether the company is still within its initial investing period, which is less than 7 years from the company's first commercial sale (or, if not, how the company will satisfy one of the two exceptions to this rule). If the company is within 7 years, then you'll need to select ‘yes’ and let HMRC know if you have made a commercial sale and when this was.
For the next question on this page, click on the ‘yes’ button only if your company is a subsidiary or if it’s the TopCo of a subsidiary. You'll then need to select which company carries out the trading activity. You will also need to upload a group structure diagram of your company structure to your application before submission, which your reviewer can provide guidance for if you’re not aware of how to do this.
The next page is about which share class you’ll be issuing for your raise. S/EIS shares must always be ordinary shares without preferential rights, so you'll need to ensure that the share class you select below is eligible.

The next page is simply asking for your business’ address.

If your company was not incorporated in the UK you'll need to make sure your company details on the ‘company details’ page are set to reflect this so that you are applying as an overseas company, then enter your non-UK address and UK permanent establishment details/address, if you have them (again, your advance assurance reviewer will guide you through this process).
Additionally, as part of the application for a company that wasn't incorporated in the UK, you'll need to submit an additional letter to address the permanent establishment requirement. This is something that the team will be able to assist you with.

In the next section, you’ll either give consent to SeedLegals to communicate with HMRC on your behalf, or add your own contact details to receive direct communication. To allow the team to handle all communications with HMRC for you, select “to the government gateway email’. To handle communications yourself or with your own team, select ‘to a different email address’.
If giving us consent, please read the DSC1 guidance and select Yes. Otherwise, select no for the second question.

The next page is about your financials. Choose one of the three options here. If you have filed accounts with Companies House, you do not need to supply a bank statement, just upload your most recently filed accounts to the platform. If you don't have accounts but have a bank statement, then answer accordingly and provide that, and if you don’t even have a bank account yet, that’s fine too! Some early-stage companies don’t have an account at the beginning, just select the 3rd option and proceed. It is not technically a requirement to have the latter the purposes of Advance assurance.

Finally, you have space to include any further details or additional information to your application. Please utilise the space to communicate something to your reviewer, or that you want HMRC to know.

2. Add your proposed investors (if you have not raised SEIS or EIS funds before)
Next, just click on "Add new" to add your proposed investors.

3. Upload your supporting documents
Once you've completed the questions and added your proposed investors, you'll need to upload your required documents. The document upload slots will be generated directly based on answers to the previous questions (Step 1). In all cases, you will need to upload your Pitch Deck, as well as any other supporting documents suggested by the platform.

4. Appoint SeedLegals as agents
The next part of the process requires you to create and sign a letter to appoint us as your agents, which gives us the authority to submit the application and correspond with HMRC on your behalf in relation to the application.


5. Complete & send your application to us
Once everything is completed and uploaded, you will notice that you can use our AI Health Check tool for a quick check of your application. We encourage you to do run this as it will flag any items that are missing or need amendments still which in turn will help speed up the application process. You can rerun the check as many times as you wish.

Once you've made the recommended amendments please click the 'submit for review' button to send the application to our team for a final review. We typically take 3-5 business days to review everything. After this, your dedicated S/EIS associate will send you an email with a review including changes that need to be made. After you have actioned these points, once finalised, we'll then submit the application to HMRC on your behalf.