Bulgaria - United Kingdom BIT (1995)

Bilateral Investment Treaties

Terminated

11/12/1995

24/06/1997

01/01/2026

Terminated by consent

en | bg

Mapped

Not mapped

Amendment protocols

Date of signature Date of entry into force Files
16/09/2025 01/01/2026 en

Mapped treaty elements


Expand / collapse all

Reference to right to regulate (e.g. regulatory autonomy, policy space, flexibility to introduce new regulations)
No
Reference to sustainable development
No
Reference to social investment aspects (e.g. human rights, labour, health, CSR, poverty reduction)
No
Reference to environmental aspects (e.g. plant or animal life, biodiversity, climate change)
No

Definition of investment
Type of definition
Asset-based definition
Limitations to the definition of investment
Excludes portfolio investment
No
Excludes other specific assets (e.g. sovereign debt, ordinary commercial transactions, etc.)
No
Lists required characteristics of investment
No
Contains "in accordance with host State laws" requirement
Yes
Sets out closed (exhaustive) list of covered assets
No
Definition of investor
Definition included
Yes
Specifying natural persons covered
Includes permanent residents
No
Excludes dual nationals
No
Specifying legal entities covered
Includes requirement of substantial business activity
No
Defines ownership and control of legal entities
No
Denial of benefits (DoB)
DoB clause included
No
Content of the DoB clause
"Substantive business operations" criterion
Not applicable
Applies to investors from States with no diplomatic relations or under economic/trade restrictions
Not applicable
Discretionary ("Party may deny") or mandatory ("benefits shall be denied")
Not applicable
Substantive scope of the treaty
Limiting substantive scope of the treaty
Excludes taxation
No
Excludes subsidies, grants
No
Excludes government procurement
No
Excludes other subject matter
No
Temporal scope of the treaty
Investments covered
Applies to both pre-existing and post-BIT investments
Disputes covered
Carves out pre-existing disputes

National treatment (NT)
Type of NT clause
Post-establishment
Reference to "like circumstances" (or similar)
No
Most-favoured-nation (MFN) treatment
Type of MFN clause
Post-establishment
Exceptions from MFN obligation
Economic integration agreements
Yes
Taxation treaties
Yes
Procedural issues (ISDS) or substantive IIA standards
No
Fair and equitable treatment (FET)
Type of FET clause
FET unqualified
FET qualified
By reference to international law
None
By listing FET elements (exhaustive or indicative list)
No
FET modifiers
None
Full protection and security
Standard
Prohibition on unreasonable, arbitrary or discriminatory measures
Yes
Expropriation
Scope of measures covered
Indirect expropriation mentioned
Refining expropriation clause
Indirect expropriation defined
Yes
Carve-out for general regulatory measures
Yes
Carve-out for compulsory licenses in conformity with WTO
No
Protection from strife
Specifications
Relative right to compensation (comparator)
MFN only
Absolute right to compensation in certain circumstances
No
Transfer of funds
Includes transfer of funds
Yes
Exceptions to the transfer of funds obligation
Balance-of-payments exception
No
Other specific exceptions (e.g. to protect creditors, etc.)
No
Prohibition of performance requirements (PRs)
Includes prohibition of PRs
No explicit PR clause
Type of PR clause
Not applicable
Umbrella clause
No
Entry and sojourn of personnel (subject to local laws)
No
Senior management (nationality)
No

Transparency
Directed at States (obligation to publish laws and regulations)
No
Directed at investors
No
Health and environment (any mentioning in the text, except preamble)
No
Labour standards (any mentioning in the text, except preamble)
No
Right to regulate (any mentioning in the text of this or similar concepts, except preamble)
No
Corporate social responsibility (any mentioning in the text, except preamble)
No
Corruption (any mentioning in the text, except preamble)
No
Not lowering of standards (typically environment and/or labour standards)
No
Subrogation clause
Yes
Non-derogation clause (in case of IIA’s conflict with other norms, more favourable rules apply to investors)
Yes
Investment promotion
Reference to specific promotion activities in text of agreement (not preamble)
No

Essential security exception
Exception included
No
Exception defined (exceptional circumstances described in more detail)
No
Exception self-judging
No
General public policy exceptions
Public health and environment
No
Other public policy exceptions (e.g. cultural heritage, public order, etc.)
No
Prudential carve-out (concerns financial measures)
No
Scheduling and reservations (in treaty texts and annexes)
None

SSDS included
Yes

ISDS included
Yes
Alternatives to arbitration
None
Scope and consent
Scope of claims: general approach (chapeau paragraph of ISDS clause)
Covers any dispute relating to investment
Limitations to the scope of ISDS
Limitation of provisions subject to ISDS
No
Exclusion of policy areas from ISDS
No
Special mechanism for taxation or prudential measures
No
Type of consent to arbitration
Provides express or implied consent
Forums
ISDS forum options
Domestic courts of the host State
No
ICSID
Yes
UNCITRAL
Yes
Other forums
Yes
Relationship between forums
No reference
Other specific ISDS features
Limitation period for submission of claims
No
Provisional measures
No
Consolidation of claims
No
Limited remedies (specifying available types of remedies)
No
Treaty interpretation
Affirms binding interpretation by contracting parties or their joint committee
No
Requires certain questions to be submitted to contracting parties (renvoi)
No
Regulates submissions by non-disputing State party
No
Transparency in arbitral proceedings
Requires documents to be made publicly available
No
Requires hearings to be open to the public
No
Regulates amicus curiae submissions by third (non-disputing) parties
No

Mechanism for consultations between State parties
No
Institutional framework (committee)
No
Technical cooperation/capacity building
No

Treaty duration
Years of initial treaty term
10 years
Automatic renewal
Indefinite term
Amendment and termination
Unilateral termination
Includes modalities for unilateral termination
Yes
Length of notice period
One year prior notice
Includes modalities for amendment or renegotiation
No
"Survival"/"sunset" clause length
20 years

Hacettepe University Faculty of Law (Turkey); University of Buenos Aires (Argentina)

The IIA Mapping Project is a collaborative initiative between UNCTAD and universities worldwide to map the content of IIAs. The resulting database serves as a tool to understand trends in IIA drafting, assess the prevalence of different policy approaches and identify treaty examples.

For more information on the project, please read the Mapping Project Description & Methodology .

  • UNCTAD's Work Programme on International Investment Agreements (IIAs) actively assists policymakers, government officials and other IIA stakeholders to reform IIAs with a view to making them more conducive to sustainable development and inclusive growth.

    International investment rulemaking is taking place at the bilateral, regional, interregional and multilateral levels. It requires policymakers, negotiators, civil society and other stakeholders to be well informed about foreign direct investment, international investment agreements (IIAs) and their impact on sustainable development.

    Main goals of UNCTAD’s Work Programme on IIAs

    • Reform the international investment agreements (IIAs) regime to enhance its sustainable development dimension,

    • Provide comprehensive analysis on key issues arising from the complexity of the international investment regime,

    • Develop a wide range of tools to support the formulation of more balanced international investment policies.

    The three pillars of activities

    • Research and policy analysis: monitoring trends, identifying key emerging issues and providing cutting-edge knowledge on IIAs from a sustainable development perspective,

    • Technical assistance: delivering trainings, seminars and workshops; conducting IIA and model BIT reviews; offering ad-hoc advice to strengthen the capacity of beneficiaries in handling the complexities of the IIA regime,

    • Intergovernmental consensus-building: exchanging and sharing best practices and experience with the view to fostering global investment governance.

    For further information, please contact us via the online contact form.

    IIA Navigator

    This database of IIAs – the IIA Navigator – is maintained by UNCTAD’s IIA Section. You can browse through IIAs concluded by a particular country or country grouping, view recently concluded IIAs, or use the Advanced Treaty Search for sophisticated searches tailored to your needs.
    Please cite as: UNCTAD, International Investment Agreements Navigator, available at https://investmentpolicy.unctad.org/international-investment-agreements/

    IIA Mapping Project

    The IIA Mapping Project is a collaborative initiative between UNCTAD and universities worldwide to map the content of IIAs. The resulting database serves as a tool to understand trends in IIA drafting, assess the prevalence of different policy approaches and identify treaty examples.

    The “Mapping of IIA Content” allows browsing through the project results to date (the page is regularly updated as the new results come in).
    Please cite as: UNCTAD, Mapping of IIA Content, available at https://investmentpolicy.unctad.org/international-investment-agreements/iia-mapping

    For more information:
    Mapping Project page
    Project Description & Methodology document

  • IIA Navigator

    International investment agreements (IIAs) are divided into two types:
    (1) bilateral investment treaties and (2) treaties with investment provisions.

    A bilateral investment treaty (BIT) is an agreement between two countries regarding promotion and protection of investments made by investors from respective countries in each other’s territory. The great majority of IIAs are BITs.

    The category of treaties with investment provisions (TIPs) brings together various types of investment treaties that are not BITs. Three main types of TIPs can be distinguished:

    1. broad economic treaties that include obligations commonly found in BITs (e.g. a free trade agreement with an investment chapter);

    2. treaties with limited investment-related provisions (e.g. only those concerning establishment of investments or free transfer of investment-related funds); and

    3. treaties that only contain “framework” clauses such as the ones on cooperation in the area of investment and/or for a mandate for future negotiations on investment issues.

    In addition to IIAs, there also exists an open-ended category of investment-related instruments (IRIs). It encompasses various binding and not-binding instruments and includes, for example, model agreements and draft instruments, multilateral conventions on dispute settlement and arbitration rules, documents adopted by international organisations, and others.

    IIA Mapping Project

    Key concepts

    - The mapping structure, displayed in the “Select mapped treaty elements” tab, is a “table of contents” that includes all of the mapped treaty elements. It corresponds to the typical structure of an IIA.

    - The mapped treaty elements are elements of an investment treaty mapped in the course of the IIA Mapping Project. The number of mapped treaty elements exceeds 100. Each mapped treaty element has a set of pre-defined mapping options to choose from.

    - The mapping options indicate the approach taken in the treaty to the relevant mapped treaty element. Mapping options can be of the “Yes/No” type or they can indicate the treaty approach more specifically (e.g. the type of fair and equitable treatment clause (FET) – qualified / unqualified / none etc.). Each mapped treaty element includes the “Inconclusive” and “Not applicable” options.

    Search tips

    “Select mapped treaty elements” tab:

    • By default, the tab shows the highest-level headings within the mapping structure. Click on the relevant heading to expand individual sections, or click on the “Expand/Collapse All” button to see all mapped treaty elements.
    • To generate a list of treaties that satisfy a certain option under a mapped treaty element, find the element in the mapping structure and select the desired option (e.g. Preamble / Reference to sustainable development / Yes).
    • Once a selection is made, the list of treaties is updated automatically, so that only treaties that correspond to the selected option are listed (the resulting number of treaties appears in the orange bar above the listed treaties, which also displays the total number of mapped treaties, e.g. “43 out of 1437 mapped treaties”).
    • If more than one option is selected under the same mapped treaty element, the system displays treaties that correspond to at least one of the options selected (i.e. results are combined). For example, a selection of “Type of FET clause”: “FET unqualified” and “FET qualified” will generate a list of mapped treaties that contain either type of clause.
    • If more than one option is selected under different mapped treaty elements, the system displays only those treaties that correspond to all of the parameters/options selected. For example, a selection of “Type of FET clause”: “FET qualified” and “Type of MFN clause”: “Post-establishment” will generate a list of mapped treaties that fulfil both criteria at the same time.


    “Filter by country, type, status, year” tab:

    • To apply an additional filter or filters, click on the “Filter by country, type, status, year” tab, expand the relevant filter(s) and make a selection.
    • Once a selection is made, the list of treaties is updated automatically, so that only treaties that correspond to the selected option are listed (the resulting number of treaties appears in the orange bar above the listed treaties, which also displays the total number of mapped treaties, e.g. “905 out of 1437 mapped treaties”).
    • The additional filters under “Filter by country, type, status, year” can be used on their own or in combination with the “Select mapped treaty elements” tab (e.g. to generate a list of BITs in force concluded between 2005 and 2015 whose preambles contain a reference to sustainable development).
    • If more than one option is selected under the same additional filter, the system displays treaties that correspond to at least one of the options selected (i.e. results are combined). For example, selecting “Argentina” and “Austria” in the “Country” filter will generate a list of mapped treaties signed either by Argentina or by Austria.
    • If more than one option is selected under different additional filters, the system displays only those treaties that correspond to all of the filters/options selected. For example, selecting “BITs” in the “Type of agreement” filter and “In force” in the “Status” filter will generate a list of mapped treaties that fulfil both criteria at the same time.


    Individual treaty mapping and text:

    • To view the full mapping of any individual treaty listed, click on any individual treaty name in the “short title” column (opens in a new tab) and scroll down to the “Mapped treaty elements” (click “Expand / collapse all” to see all elements.
    • The text of any treaty listed can be accessed through the link or links in the “Text” column (opens in a new tab).
    • For additional information on any individual treaty, click on the treaty’s “Short title”.


    “Expand/Collapse All” and “Clear selection” buttons:

    • The respective buttons apply only to the tab that is currently active, i.e. the “Select mapped treaty elements” tab or the “Filter by country, type, status, year” tab. To apply a button in both tabs, click the button in the current tab, then switch to the other tabs and click the button again.

  • Disclaimer

    The IIA Navigator is continuously adjusted as a result of verification with, and comments from, UN Member States. It is primarily built on information provided by governments on a voluntary basis. A treaty is included in a country's IIA count once it is formally concluded; treaties whose negotiations have been concluded, but which have not been signed, are not counted. A treaty is excluded from the IIA count once its termination becomes effective, regardless of whether it continues to have legal effect for certain investments during its “survival” (“sunset”) period.

    While every effort is made to ensure the accuracy and completeness of its content, UNCTAD assumes no responsibility for eventual errors or omissions in these data. The information and texts included in the database serve a purely informative purpose and have no official or legal status. In the event of doubt regarding the content of the database, it is suggested that you contact the relevant government department of the State(s) concerned. Users are kindly asked to report agreements, errors or omissions by using the online contact form.

    The IIA Mapping Project is a collaborative initiative between UNCTAD and universities worldwide to map the content of IIAs. Individual treaties are mapped by law students from participating universities, under the supervision of their professors and with the overall guidance and coordination of UNCTAD.

    The mapping results included in the IIA Mapping Project database serve a purely informative purpose. The mapping of treaty provisions is not exhaustive, has no official or legal status, does not affect the rights and obligations of the contracting parties and is not intended to provide any authoritative or official legal interpretation.

    While every effort has been made to ensure accuracy, UNCTAD assumes no responsibility for eventual errors or omissions in the mapping data. In the event of doubt regarding the correctness of mapping results, users are kindly asked to contact us via the online contact form.