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Plantsea

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Seaweed-based polymers to replace soluble plastics (PVOH) for sustainable packaging.

168%
 - 
Funded 20 Jan 2026
£500,005 target
£844,778 from 551 investors
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Business overview

Location St. Asaph, United Kingdom
Social media
Website plantsea.co.uk/
Sectors Energy Non-Digital B2B
Company number 12551709
Incorporation date 8 Apr 2020
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Investment summary

Type Equity
Valuation (pre-money) £6M
Equity offered 12.30%
UK tax relief

EIS

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Business highlights

  • £20M Pipeline of qualified customers
  • £7.5M in LOI's secured
  • Biorefining process scaled from 2L to 500L
  • Validated on manufacturing and packaging lines
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Key features

  • Secondary Market
  • Nominee investment min. £25.10 +
  • Direct investment min. £10,000.00 +

Pitch

About the Campaign

PlantSea's award-winning solution replaces plastic in laundry capsules with a scalable, low-cost, seaweed polymer.

Backed by up to £7.5M in value in LOIs, paid FMCG trials, and a patent-pending technology.

We're opening the door to 'plastic-free packaging' in multiple global sectors (food, pharma, industrial)

Market Opportunity

Regulatory and consumer pressure is driving brands to eliminate hidden plastics.

Targeting the laundry capsule market, forecast to be worth $19B by 2030, PlantSea offers a cost-competitive, drop-in plastic-free alternative.

Unlocking demand across the $1.6B PVOH polymer market for packaging and industrial applications.

Traction & Key Accomplishments

PlantSea has secured £7.5M in LOIs and a £20M+ pipeline across global film manufacturers, major FMCGs, household product producers, food packaging converters, and premium consumer brands.

Key customer demand forecasts range from millions of metres of film to hundreds of tonnes of polymer annually.

Biorefining, film-casting and packaging trials have validated scalability, while paid pilots have already generated early revenue and demonstrate strong market pull toward commercial rollout.

Use of Funds

Funds will scale production with key partners, expand our technical and commercial teams, and secure key certifications and IP.

With the funds from this round, we aim to achieve revenue generation from early adopters and position PlantSea to convert pilots into long-term offtake contracts, reducing future funding needs.

Key Information

Key information investment sheet

Key Investment Information Sheet is available by downloading the following documents:

Share Classes

The Company currently has three classes of shares: Ordinary Shares, Ordinary A Shares, and Preferred Ordinary Shares.

All investors in this round, including Republic Europe investors, will receive Ordinary A Shares.

Holders of Ordinary Shares, Ordinary A Shares, and Preferred Ordinary Shares will receive full voting and dividend rights.

On a liquidation, return of capital or exit, the proceeds will be distributed as follows:

(1) First, Preferred Ordinary Shareholders will receive a return equal to repayment of their issue price.

(2) Second, the remaining proceeds are shared among all shareholders according to their holdings. Ordinary Shareholders and Ordinary A Shareholders will participate equally in the remaining distribution.

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Only shareholders can access this page

If you successfully purchase a share lot of this business, you will be granted access.

Buy shares

Only shareholders can access this page

If you successfully purchase a share lot of this business, you will be granted access.

Buy shares

Only shareholders can access this page

If you successfully purchase a share lot of this business, you will be granted access.

Buy shares

Investing involves risks, including loss of capital, illiquidity, lack of dividends and dilution, and should be done only as part of a diversified portfolio. Please read the Risk Warnings before investing. Investments should only be made by investors who understand these risks. Tax treatment depends on individual circumstances and is subject to change in future.

This campaign for Plantsea has been approved by Seedrs Limited (trading as Republic Europe) ("Republic Europe", "us" or "we"), as of 12 December 2025 as a financial promotion. Republic Europe is authorised and regulated by the Financial Conduct Authority with firm reference number 550317. In approving this campaign, Republic Europe has concluded that the information, taken as a whole, is "fair, clear and not misleading." This means that for factual statements we have reviewed evidence of their accuracy, and that for aspirational statements we believe they are phrased appropriately in light of their speculative nature. You should note that in the case of factual statements, the evidence we review is provided by the business, and we do not audit it, which means that we may not be able to identify forged or altered evidence. You should further note that in the case of aspirational statements, the nature of the type of businesses presented on the Republic Europe platform is such that they are likely to have high ambitions, and we may approve statements that convey those ambitions even where we do not believe, or we do not have a view on whether it is likely, that they will be fully realised. The pre-money valuation and investment sought in the campaign are those set by the business: they are not reviewed or established by us, and the valuation is not an independent view of what the business is worth. Given the nature and type of businesses presented on the Republic Europe platform, it is possible that the business has very little cash remaining prior to receiving this investment, and the investment sought may be necessary for the business's on-going existence.

Republic Europe does not make investment recommendations to you. No communications from Republic Europe, through this website or any other medium, should be construed as an investment recommendation. Further, nothing on this website shall be considered an offer to sell, or a solicitation of an offer to buy, any security to any person in any jurisdiction to whom or in which such offer, solicitation or sale is unlawful. Republic Europe does not provide legal, financial or tax advice of any kind. If you have any questions with respect to legal, financial or tax matters relevant to your interactions with Republic Europe, you should consult a professional adviser.

Tax Relief (SEIS)

This business is eligible for SEIS relief - providing qualifying investors with income tax relief of 50% of their investment and certain other tax reliefs. Tax treatment depends on individual circumstances and is subject to change in future. Click to learn more.

Tax Relief (EIS)

This business is eligible for EIS relief - providing qualifying investors with income tax relief of 30% of their investment and certain other tax reliefs. Tax treatment depends on individual circumstances and is subject to change in future. Click to learn more.

Valuation (pre-money)

Valuation rounded from £6,004,497

This is the fully-diluted pre-money valuation of the business (i.e. before the new investment comes in and including issued options and other equity interests). In contrast, the post-money valuation is based on inclusion of the new investment in the value.

It is calculated as the pre-money valuation plus the amount of new investment. e.g. If Company A is ascribed a pre-money valuation of £1,200,000 by prospective investors investing £300,000, its post-money valuation is £1,500,000.

The investee business is responsible for setting its own valuation, it has not been prescribed by Republic Europe.

Pitch type

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Equity Offered

The equity offered is the percentage of the company’s shares being issued in return for the amount of investment raised.

When the amount raised is less than 100%, the equity offered is based on the target raise. Once the company has raised over 100% it is based on the total raised.

In some scenarios, entrepreneurs may accept additional direct investment after closing their Republic Europe campaign. Provided this is within 6 months of the closing and on the same terms, we do not typically offer pre-emption rights on that extra investment (where you have the opportunity to invest again to maintain your percentage shareholding).

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Nominee investment

This shows if you are able to choose, when making an investment, that you be represented by, and your shareholding be managed by, the Nominee investment.

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Custodian

If you invest in this Campaign, Republic Europe will act as Custodian rather than provide our standard nominee service. This is due to the fact that the business is not directly involved in the share sale and Republic Europe will not benefit from any rights under a shareholder agreement. As a result, Republic Europe will handle administrative tasks as we do normally, but you will not have information or voting rights, updates from the business, preemption on future fundraising, or ongoing support about business trading activity.

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Secondary market

This shows if the business has opted-in or opted-out of allowing its shares to be bought and sold on the secondary market.

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Direct investment

If available, this is an option to invest and hold shares 'directly' in the company (rather than via the Nominee investment). This option is only available to those investing over the threshold amount, which is determined by the fundraising company.

If you choose to hold your shares directly, you will be responsible for any contractual or administrative arrangements with the company you are investing in.

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Payment options

We are not able to accept card payments for investments into this sector. You can pay for your investment by creating a bank transfer, using funds in your investment account or create a Pay by Bank payment. Your investment will only be completed once the funds have reached our account.

Business Involvement

This Campaign offers shares for sale in business that is not directly involved in this Campaign or the sale. As a result, the Campaign and post-investment experience, including investor rights, will differ from a business-led campaign on Republic Europe. Most notably, the business will not engage with investors in the discussion forums both during and after the sale or provide any updates to investors.

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Payment options

We are not able to accept Pay by Bank payments for investments into this sector. You can pay for your investment with a card payment, by creating a bank transfer or by using funds in your investment account. Your investment will only be completed once the funds have reached our account.

Drawdowns

This campaign offers the ability to pay for an investment by drawdowns.

Security Token

A security token is a digital asset that represents ownership or other rights. It is a digital form of traditional investments. In the future, you may be able to trade your investment through compatible exchanges.

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