Sustainability (MDPI) APC and Open Access: Fees, Discounts, and a Submission Budget

MDPI's policy describes institutional agreements, reviewer vouchers and selected invitations. Support is conditional, and a general program description is not an award to your paper. Do not assume a full waiver for authors in low-income countries, a standard early-career discount or a fixed editorial-board percentage without confirmation. MDPI discount and waiver policy.

Institutional support: Check whether your institution participates in MDPI's Institutional Open Access Program (IOAP) and which authors, journals and submission conditions qualify. An agreement can involve a discount or coverage; those are different outcomes for the author. Ask your library who pays any remaining balance and whether approval is required before submission.

Reviewer vouchers: MDPI describes these as non-transferable. They can apply to papers where the reviewer is an author. Reviewer vouchers may combine with other reviewer vouchers and institutional or affiliated-society discounts under the policy. Do not add an author to obtain a voucher or treat a colleague's unused code as laboratory credit. MDPI APC payment FAQ.

Invited submissions: A special-issue invitation does not by itself establish a reduced price. Read any personal offer, its eligible paper and deadline. Ask the office whether it can combine with another benefit before assuming a total discount. MDPI invited-submission discounts.

Financial need without confirmed support: Tell the journal office what funding is available and ask whether assistance can be considered. Budget the full charge until you receive an answer. This is a suggested inquiry, not a claim that a hardship application must succeed.

The operational deadline matters: MDPI's FAQ says eligible discounts must be applied before acceptance and cannot be added once the APC invoice is issued. Check the submission record early enough to correct an omitted benefit. Discount application and invoice rules.

In our editorial assessment, the useful decision is whether an author has an approved route to pay the actual bill. A fee comparison cannot answer that. We use the following budget card to separate publisher terms from a funder's willingness to reimburse them. This is Manusights' planning framework, not a report of measured author outcomes.

Copy this budget card into your submission notes:

1. Identity: Journal name, publisher and manuscript category. Confirm that the quote belongs to MDPI's Sustainability.
2. Price: Listed APC, currency and the date or submission terms to which it applies.
3. Reduction: Discount type, amount, eligible author and confirmation reference. Write “not confirmed” for a pending request.
4. Invoice: Billing name, tax details, invoice currency and the person responsible for checking it.
5. Coverage: Approved payer, maximum amount and remaining funds. An institutional discount does not necessarily mean institutional payment.
6. Timing: Any approval deadline, grant end date or service-order requirement that could prevent reimbursement.
7. Decision: Submit with an approved budget, resolve an identified gap first, or compare another journal with a suitable scope and funding route.

Keep separate totals for the publisher's charge and the author's remaining exposure. A grant may pay the whole invoice, part of it or none of it. Subtracting a grant contribution from the APC does not turn that contribution into a publisher discount.

Worked example: covered APC, uncertain tax

Suppose a fictional author has written approval for the CHF 2,400 base fee but has not checked VAT or sales tax. Their approved funding does not yet prove the invoice is fully covered. The next action is to confirm tax treatment and the funding ceiling with the finance office. It is not to search for an optimistic dollar conversion.

If no tax applies and the payer confirms the whole charge, the author's own contribution can be zero even though the journal still charges an APC. If tax or currency costs exceed the approval, the budget card reveals the gap before submission. These are planning cases, not tax calculations or publisher quotes.

Worked example: a discount without a payer

Suppose a second fictional author is eligible for a reduction but has no funding approval. A lower invoice is still an unpaid invoice. They should obtain the confirmed net price and decide how the remaining amount would be paid. An invitation, reviewer voucher and eligible institution are evidence to investigate, not three savings to add automatically.

This is the common budget failure pattern the card is designed to catch: “eligible for a discount” becomes “publication is funded” without a payer agreeing to the balance. Keep the approval step visible even when a reduction looks substantial.

Keep the base budget in CHF until the publisher confirms another invoice currency. If your institution works in USD or EUR, record its chosen exchange-rate date and any buffer as your finance team's estimate. Do not present a converted amount as MDPI's guaranteed charge.

Record VAT or sales tax separately from any currency buffer. The publisher determines the invoice; your finance office determines what its approval covers. If either is unresolved, hold the funding decision until the missing amount or approval is confirmed.

Before acceptance, check the billing identity, address and currency in the submission record. MDPI provides a process for updating invoice details, and its FAQ distinguishes that process from adding discounts. MDPI invoicing FAQ.

Treat an optional editing order as a separate purchase decision. Specify its scope and price before authorizing it; do not assume it is required for acceptance or included in an institutional APC approval. Scientific readiness remains a separate question. A Sustainability (MDPI) submission readiness check can help you examine scope and evidence concerns before committing.

For invoice authenticity, return to the publisher's official payment instructions. Sustainability's fee page warns that MDPI does not authorize third parties to collect its APC. Verify a questionable request through an independently opened publisher contact route. Official journal invoice notice.

Sustainability publishes in full open access. Check the article licence and the actual award terms together. Access to the publisher's version does not by itself establish that every repository, acknowledgement or eligible-cost requirement has been met.

Use a short question set with your library or research office:

• Does this award require a particular licence, and will this manuscript use it?
• Does a copy also need to be deposited in a named repository?
• Are funding acknowledgements or data requirements specified?
• Is this journal's APC an eligible expense under the award?
• Must the institution approve payment before submission or acceptance?

Do not use a universal “all major funders: yes” table in place of these answers. For a Plan S, NIH, UKRI, ERC, Wellcome or Horizon Europe award, consult the policy that actually applies to that award and submission. This guide does not certify funder compliance.

No year-by-year Sustainability APC trend is asserted here. A current price does not establish a historical increase, and an old Manusights price is not publisher evidence. Verify historical APC values from dated publisher records before using a trend in a grant budget.

MDPI's July 2026 price-change notice specifies the affected journals and submission-date boundary. Sustainability is not listed in that notice. This supports checking journal-specific terms rather than assuming every MDPI journal changed price together. Keep the confirmation for your own submission even when an annual notice leaves the journal unchanged.

Search results for “sustainability APC” include several distinct journals. Match the publisher and title before copying a fee into your budget. These are identity checks, not interchangeable recommendations.

For example, a quote found under Communications Sustainability does not reduce the MDPI fee. Once the journal identity is clear, return to the budget card and record the actual submission terms for that title.