The original NFT standard was intentionally simple. ERC-721 created a common interface for identifying an individual token, checking its owner, approving an operator and transferring the token between Ethereum addresses.

That simplicity enabled wallets, marketplaces and applications to support NFTs without building a separate integration for every collection. It also left many product-level questions unanswered.

ERC-721 does not define a universal rental role. It does not tell marketplaces when metadata changes. It does not make a token non-transferable, allow an NFT to own other assets or create a secure connection between a blockchain token and a physical product.

Newer NFT standards attempt to address these limitations through optional extensions and specialised interfaces.

Some have reached Final status in the Ethereum standards process. Others remain under review and may still change. A published ERC proposal is therefore not automatically an adopted industry standard.

The direction is nevertheless clear: NFTs are evolving from transferable identifiers into programmable records with multiple roles, assets, permissions and external relationships.

What is an NFT standard?

An Ethereum Request for Comments, or ERC, defines an application-level interface that developers can implement consistently.

A standard does not automatically deploy software, guarantee security or force marketplaces to support it. It describes how compatible contracts and applications should communicate.

The Ethereum Improvement Proposal repository distinguishes between several lifecycle stages. A proposal marked Final represents the final standard, while a proposal marked Review is still undergoing peer review.

This distinction matters when evaluating newer NFT functionality.

A project may implement an experimental proposal successfully, but wallets and marketplaces may not recognise it. Another project may use a Final standard, yet still implement it incorrectly or combine it with insecure custom code.

Standards improve interoperability. They do not remove the need for technical review.

ERC-721 remains the foundation of unique NFTs

ERC-721 is the foundational non-fungible token standard on Ethereum. It defines a standard interface for tracking and transferring individually identifiable tokens.

Each token is distinguished by a token ID inside its collection contract. The standard includes ownership queries, transfers, individual approvals and operator approvals. Its optional metadata extension allows applications to retrieve a token name and information about the asset it represents.

ERC-721 was designed broadly enough to represent digital or physical assets. Its specification mentions unique artwork, property and collectible cards rather than limiting the standard to profile-picture collections.

What ERC-721 primarily standardises is the token record—not the complete legal or commercial relationship behind it.

It does not independently prove:

• who created the underlying work;
• whether the issuer owns copyright;
• whether a connected physical product exists;
• what licence the holder receives;
• whether advertised utility will continue;
• whether external metadata is permanent;
• whether a sale must pay creator royalties.

Those elements require additional standards, contracts, documentation and verification.

ERC-1155 supports complex collections and gaming inventories

ERC-1155 introduced a multi-token model. One smart contract can manage fungible, semi-fungible and non-fungible token types, with each token ID having its own supply, metadata and configuration.

This structure is useful for products containing many asset types.

A game could use one contract for:

• unique characters;
• limited-edition weapons;
• interchangeable resources;
• event passes;
• consumable items;
• collectible cards.

ERC-1155 also supports batch transfers, allowing several token types to move within one transaction. The standard was partly motivated by the need to avoid deploying a separate contract for every item type in large gaming and digital-asset environments.

Choosing between ERC-721 and ERC-1155 is therefore not simply a question of which standard is newer.

ERC-721 may be appropriate when each token is individually significant and external applications expect the familiar ERC-721 interface. ERC-1155 may be more efficient when one product needs many token categories, editions or batch operations.

Neither standard automatically provides secure metadata, legal ownership or cross-platform utility.

ERC-4906 helps marketplaces detect metadata changes

Dynamic NFTs create a practical indexing problem.

A marketplace may retrieve the metadata once and cache the result. If the token later changes level, status, image or another attribute, the marketplace needs a reliable signal telling it to refresh the record.

ERC-4906 adds standard MetadataUpdate and BatchMetadataUpdate events to ERC-721 contracts. When the JSON metadata for a token or a consecutive range of tokens changes, a compliant implementation emits the appropriate event so third-party applications can retrieve the updated information. The extension is optional and has Final status.

This can support:

• evolving game characters;
• changing membership status;
• updated product records;
• completed redemption status;
• refreshed certificate information;
• time-dependent visual states.

ERC-4906 does not specify which metadata fields may change or whether the changes are legitimate. It only standardises the update signal.

The standard’s security section specifically warns that functions triggering metadata updates need correct permission controls. An unrestricted update function could allow unauthorised parties to manipulate how an NFT appears in wallets or marketplaces.

A responsible project should disclose:

• which metadata is mutable;
• who can change it;
• which events trigger changes;
• whether previous versions remain available;
• whether the holder can reject an update.

ERC-7160 gives one NFT multiple metadata records

ERC-7160 extends ERC-721 so one token can have multiple metadata URIs. The holder or application can work with a pinned primary URI while the contract retains a list of other associated metadata records. The standard reached Final status and recommends using ERC-4906 when metadata choices are added or removed.

Multiple metadata records can support several models.

An intellectual product could include:

• a marketplace preview;
• a detailed verification record;
• a high-resolution version;
• a historical edition;
• an accessibility-focused format.

A gaming asset could include different representations for separate engines or devices. A product record could maintain current metadata while preserving previous revisions.

The standard does not make every listed file equally trustworthy. A malicious or compromised issuer could still add misleading content where contract permissions allow it.

Applications also need to decide whether they display:

• only the pinned record;
• all available records;
• a platform-selected record;
• the latest approved version.

Multiple metadata options improve flexibility, but they make provenance and version control more important.

ERC-5773 supports context-dependent multi-asset NFTs

ERC-5773 takes the multi-asset concept further.

A single NFT can expose different assets depending on the application accessing it. The same token could provide a PDF to an e-book reader, an audio file to an audiobook application, a visual preview to a marketplace and a 3D model to a game.

The Final standard also uses an issuer-and-owner approval model for changing or adding assets. Proposed additions can be accepted or rejected rather than allowing the issuer to replace the NFT’s content unilaterally.

Potential applications include:

• multimedia intellectual products;
• evolving game items;
• software or firmware records;
• device-specific product files;
• redundant storage references;
• collaborative digital works.

ERC-5773 can improve portability at the metadata level. It does not force separate games, readers or applications to understand the same asset in the same way.

A 3D model may be technically accessible across several platforms while remaining incompatible with their graphics engines, physics systems or gameplay rules.

Interoperability requires more than sharing a URI. Applications must also agree on formats, attributes, behaviour and permissions.

ERC-4907 separates NFT ownership from temporary usage

In many products, the owner and active user are not the same person.

A landlord can own virtual property while another user rents it. A game-item owner may lend an asset without transferring it permanently. A company may own a membership token while assigning temporary access to an employee.

ERC-4907 adds a separate user role to ERC-721. The role can be assigned until a specified expiry time, after which the user permission automatically becomes invalid. The user may use the NFT but cannot transfer it or assign another user. ERC-4907 has Final status.

The standard can support:

• NFT rentals;
• delegated game-item use;
• temporary memberships;
• event access;
• virtual land usage;
• subscription-like rights.

The automatic expiry mechanism avoids requiring a second transaction merely to remove the user role when the rental period ends. It also gives external applications a standard way to determine the current authorised user.

However, ERC-4907 does not provide an entire rental marketplace.

A complete system still needs to determine:

• payment conditions;
• security deposits;
• early termination rules;
• damage or misuse consequences;
• whether the owner can transfer the NFT during the rental;
• what happens to off-chain access after expiry.

The standard manages an on-chain role. The commercial agreement remains separate.

Soulbound standards make some NFTs non-transferable

Transferability is useful for collectibles, but inappropriate for certain personal records.

A qualification, attendance record or identity-linked credential should not necessarily be saleable to another wallet.

ERC-5192 provides a minimal interface allowing applications to determine whether an ERC-721 token is locked to an account. When locked, transfer functions must fail. The standard reached Final status.

ERC-5484 adds a more specific consensual model. Before issuance, the issuer and receiver agree on immutable burn authorisation. The token cannot be transferred after issuance, but it may be burned according to the predetermined rule. ERC-5484 also requires the issuer to present the metadata and receive the recipient’s signature before issuance.

Possible soulbound use cases include:

• training certificates;
• memberships;
• attendance badges;
• professional credentials;
• contribution records;
• account reputation.

Non-transferability creates its own risks.

A user may lose the wallet key. A wallet may be compromised. A person may need to migrate to a new address. Publicly visible credentials may also reveal sensitive information.

ERC-5484 addresses key rotation partly through burn-and-reissue procedures, but the issuer must still maintain an operational process for verifying the replacement request.

Soulbound tokens should not contain unnecessary private data. Non-transferable does not mean private.

ERC-6551 proposes token-bound accounts

ERC-6551 introduces one of the most significant expansions of NFT functionality: token-bound accounts.

The proposal assigns a smart contract account to an NFT. That account can hold assets and interact with applications, while control of the account follows ownership of the parent NFT. It can be applied without modifying the original NFT contract.

A game-character NFT could therefore own:

• weapons;
• clothing;
• achievements;
• currencies;
• companion NFTs.

A membership NFT could hold participation badges or a history of on-chain interactions. A product NFT could contain components and associated records.

As of 27 July 2026, ERC-6551 remains in Review, not Final status. The proposal itself notes security questions involving account registries, implementation choices, fraud prevention and ownership cycles.

Token-bound accounts also create new interpretation risks.

When the parent NFT is sold, control of assets held inside its account may move to the buyer. A marketplace interface that displays only the parent image may not communicate the complete contents or liabilities of the account.

Before transferring such an NFT, users need to inspect:

• which token-bound account implementation is used;
• which assets the account holds;
• whether the account has active approvals;
• whether it controls other accounts;
• whether hidden or malicious assets are present;
• whether the account can execute arbitrary calls.

Programmable ownership increases capability and attack surface at the same time.

ERC-7401 allows NFTs to own other NFTs

ERC-7401 provides a Final standard for parent-governed NFT nesting.

Under this model, an NFT can own another NFT. The child token is managed through the parent relationship, while the root parent’s owner ultimately controls the nested structure.

This can support:

• NFT bundles;
• collections grouped under one token;
• membership tokens containing benefits;
• game characters containing equipment;
• supply-chain records containing journey stages;
• delegated voting relationships.

Selling a root parent could transfer control over all accepted child NFTs as one structured unit.

This is more expressive than transferring an arbitrary collection of tokens in separate transactions. It is also more complex.

A prospective buyer must understand:

• which child NFTs are accepted;
• whether pending children exist;
• whether children can be removed;
• whether any child token is non-transferable;
• whether nested assets rely on external contracts;
• how marketplaces value and display the bundle.

Nested ownership can become difficult to audit when several levels of parent-child relationships are involved.

ERC-6956 targets physical and off-chain assets

A standard NFT can store an asset identifier in its metadata, but that identifier may be mutable, copied or disconnected from the physical object.

ERC-6956 proposes asset-bound NFTs in which a unique physical or digital anchor has a one-to-one relationship with the token. An oracle provides an attestation that control over the anchored asset has been demonstrated before actions such as minting, transferring or burning are authorised.

As of 27 July 2026, ERC-6956 remains under Review.

Its model is relevant to:

• physical collectibles;
• luxury products;
• machinery;
• product certificates;
• secure devices;
• phygital ownership systems.

The standard does not define the anchor technology itself. The physical connection could rely on a secure chip, device, tag or another method capable of proving control.

This creates a crucial limitation: the blockchain depends on the oracle and anchor system.

ERC-6956’s security discussion acknowledges that proving physical control does not necessarily prove lawful ownership. A thief controlling the asset could potentially produce the required interaction unless the system is combined with a locking or dispute mechanism.

Physical NFT standards can strengthen token-to-product integrity, but they do not replace custody procedures, legal title records or theft reporting.

ERC-2981 standardises royalty information

ERC-2981 provides a standard method for retrieving an intended NFT royalty recipient and amount.

A marketplace can supply a sale price to the token contract and receive the address and percentage-based amount that should be paid. ERC-2981 is Final and can be implemented alongside ERC-721 or ERC-1155.

The standard does not enforce payment.

Its specification makes royalties voluntary because a token transfer does not necessarily represent a sale. The actual transfer of funds remains the responsibility of the marketplace or transaction system.

ERC-2981 therefore improves interoperability between creators and marketplaces, but it does not solve universal royalty enforcement.

Collections seeking stronger enforcement may add marketplace restrictions or custom transfer validation. Those controls can reduce compatibility with open marketplaces, lending protocols and future applications.

Standards do not automatically create interoperability

Implementing the same interface allows applications to recognise certain functions. It does not guarantee that the underlying product works everywhere.

A marketplace may recognise ERC-4906 update events but ignore a custom attribute. A game may detect ERC-1155 tokens without supporting their item logic. A wallet may display a soulbound token while failing to explain why it cannot be transferred.

Practical interoperability requires several layers:

1. Contract compatibility — applications recognise the interface.
2. Metadata compatibility — applications understand the returned data.
3. File compatibility — linked media uses supported formats.
4. Utility compatibility — external products honour the same permissions.
5. Legal compatibility — rights remain valid in the relevant context.
6. Security compatibility — integrations do not introduce unsafe approvals or calls.

A token standard can solve the first layer and assist with the others. It cannot force independent applications to adopt identical business logic.

More programmability creates more security responsibility

Each new NFT capability expands the number of states and permissions that developers must secure.

A basic NFT can already expose users to:

• unsafe operator approvals;
• incorrect transfers;
• malicious marketplaces;
• vulnerable mint functions;
• mutable metadata;
• compromised administrators.

Programmable standards add further concerns.

A rental NFT needs secure user-role assignment. A multi-asset NFT needs controlled asset proposals. A token-bound account needs safe execution logic. A physical-asset NFT needs trusted attestations. A nested NFT needs clear parent-child management.

Security reviews should examine:

• access-control roles;
• upgrade authority;
• emergency controls;
• signature validation;
• replay protection;
• external contract calls;
• metadata permissions;
• token recovery procedures;
• transfer restrictions;
• interaction between combined standards.

A contract can comply with an ERC interface while containing unsafe implementation code.

Standards describe expected behaviour. Audits and testing assess whether a particular implementation follows that behaviour safely.

Projects should use the smallest suitable standards set

Adding every available extension does not create a better NFT.

Each interface increases deployment complexity, integration requirements and potential failure modes.

A project should begin with the product requirements.

A unique intellectual product

ERC-721 may be sufficient, combined with carefully structured metadata and separate licensing terms.

A large gaming inventory

ERC-1155 may support multiple item types and batch transfers more efficiently.

A changing product record

ERC-4906 can signal metadata updates. ERC-7160 or ERC-5773 may be appropriate when several asset versions or formats are required.

Temporary access

ERC-4907 can distinguish the owner from a time-limited user.

Personal credentials

ERC-5192 or ERC-5484 may support non-transferability, provided privacy and wallet-recovery risks are addressed.

Bundled or evolving assets

ERC-7401, ERC-5773 or a carefully assessed ERC-6551 implementation may support more complex ownership structures.

Physical products

A project may evaluate asset-bound models such as ERC-6956, but it still needs secure tags, oracle governance and real-world custody procedures.

The contract should reflect the actual utility rather than acting as a catalogue of technical features.

Questions to answer before selecting an NFT standard

Before development begins, the project team should document:

• What does the token represent?
• Is each unit unique or are multiple copies required?
• Must the token be transferable?
• Can the owner and active user be different?
• Will metadata change?
• Who controls metadata updates?
• Does the token need several media formats?
• Can it contain or own other tokens?
• Is it connected to a physical product?
• Does the project depend on an oracle?
• Which marketplaces and wallets must support it?
• What happens if the application closes?
• How will rights and licences be documented?
• Can the contract be upgraded?
• Which administrator permissions remain after launch?

The selected standard should produce the clearest and safest record—not the most technically impressive one.

Frequently asked questions about new NFT standards

Is ERC-721 outdated?

No. ERC-721 remains the foundational standard for individually identifiable NFTs. Newer ERCs usually extend it for specialised use cases rather than replace it.

What is the difference between ERC-721 and ERC-1155?

ERC-721 tracks individually unique tokens. ERC-1155 allows one contract to manage multiple fungible, semi-fungible and non-fungible token types and supports batch operations.

Which standard supports dynamic NFT metadata?

ERC-4906 standardises events that notify applications when token metadata changes. ERC-7160 supports multiple metadata URIs, while ERC-5773 supports context-dependent multi-asset output.

Can an NFT be rented without transferring ownership?

ERC-4907 provides a separate, time-limited user role. The owner retains ownership while another address receives temporary usage permission.

What standard makes an NFT non-transferable?

ERC-5192 provides a minimal soulbound interface. ERC-5484 adds predetermined burn authorisation and receiver consent before issuance.

Can an NFT own other assets?

ERC-6551 proposes token-bound accounts that can hold assets and interact with applications. ERC-7401 provides a Final standard for nesting child NFTs inside parent NFTs.

Can a standard prove that a physical product is authentic?

No standard can establish physical authenticity by blockchain data alone. Asset-bound proposals can connect token actions to anchors and oracle attestations, but the system still depends on the security of the physical identifier and verification process.

Does ERC-2981 guarantee creator royalties?

No. It standardises royalty information. Marketplaces must still choose or be technically required through another mechanism to execute the payment.

Does Final status mean a contract is secure?

No. Final status means the interface has completed the standards process. A specific implementation may still contain vulnerabilities, incorrect permissions or unsafe integrations.

NFT standards are becoming product architecture

The first generation of NFT standards answered a narrow question: who owns this token, and how can it be transferred?

Newer standards address more complex relationships:

• who may temporarily use the token;
• when its metadata changes;
• which version should be displayed;
• whether it can be transferred;
• what assets it contains;
• whether it owns other NFTs;
• how it connects to a physical object;
• which creator royalty information applies.

This evolution makes NFTs more suitable for gaming, memberships, intellectual products, credentials, product records and phygital systems.

It also makes implementation decisions more consequential.

Programmable ownership is not simply ownership with more features. It is a network of permissions, dependencies and external responsibilities that must be documented and secured.

The strongest NFT project will not necessarily use the newest standard.

It will use the smallest set of mature, compatible interfaces required to represent the product accurately—and clearly disclose everything those interfaces cannot prove.

Risk notice: This article is provided for general educational and informational purposes. It is not technical, legal, financial or investment advice. ERC proposals and implementation practices may change. Smart contracts should be independently reviewed and tested before production use.