MDPI Invoicing FAQ

1. I'm trying to pay the invoice online, but I’m getting a payment error. What should I do?

Below are some payment troubleshooting suggestions:

  • Ensure your credit card is authorised for international transactions.
  • If you are unable to access, please try using a different web browser (if available), or try disabling any add-ons in your browser that might be blocking the transaction.
  • Check if your credit card has a spending limit.
  • If the page returns an error after entering your credit card details, your card provider may have blocked the transaction. To resolve this issue, you will need to contact your credit card provider.
  • International credit cards often require a two-factor authentication process, such as 3D Secure, for international transactions. This may involve verifying your identity with the card issuer by providing a code sent via SMS or email. You may be required to complete both steps in the process before payment can be authorised.

If you are unable to resolve the issue, please see our Payment Instructions for alternative payment options.

2. How can I modify the address in my invoice? Can someone else pay my invoice?

MDPI allows the corresponding and submitting author to update the invoice information by following the link provided in the invoice email or in the Submissions Menu under Invoices.

You can modify the billing address, email address and invoice currency. Please note that the modified invoice can be downloaded immediately after the update.

3. Is it possible to split the APC invoice amount between the authors?

It is possible to split a single invoice into up to eight parts. Please send your request to and specify how many parts you would like the invoice split into, and provide a new billing address for each part. Please note that each part will have its own new ID and a payment link for online settlement.

4. Which currencies do you accept? Can I change the currency in my invoice?

We accept payments in Swiss Francs (CHF), US Dollars (USD), Euros (EUR), Pounds Sterling (GBP), Japanese Yen (JPY) and Canadian Dollars (CAD). For more detailed information, please visit our Payment Instructions.

You may change the currency of the invoice by using the link provided in your APC Invoice email or accessing the invoice through your profile under the Submissions Menu in Invoices.

5. Does MDPI offer any discounts or waivers on the APC?

MDPI has an Institutional Open Access Program (IOAP) which grants authors affiliated with participating institutions discounts on our APC.

Reviewers who provide timely and substantial comments will receive a discount voucher code entitling them to an APC reduction. Vouchers will be sent to reviewers only after the final decision of the reviewed paper is given. All valid and associated vouchers can be applied to one invoice.

Note that vouchers issued to specific individuals are not transferable. Only vouchers that were issued to one of the authors of the current paper are valid and must be mentioned during the submission process.

Please note that reviewer vouchers must be applied before acceptance for publication. Vouchers can no longer be applied once an APC invoice has been issued.

6. I have a discount voucher and I want to apply it to my paper. How do I proceed?

Discount vouchers will be shown under the Submissions Menu in the Discount Vouchers list. In order to be able to use all vouchers sent from MDPI, authors are allowed to link multiple emails to the current profile being used.

Please add your voucher code in the MDPI system when you submit your paper, then, you will automatically receive a reduction on the APC.

Note that vouchers cannot be used after an invoice has been issued. In case of rejection, the voucher can be reapplied in your next submission. If you are not sure how to apply your voucher, please contact the assigned editor.

Authors affiliated with participating universities receive up to one IOAP discount on the APC for any paper published in an MDPI journal which may be combined with reviewer vouchers.

7. My discount is not reflected on the invoice I have received. I have been offered to publish free of charge and I would like to take advantage of this. What should I do?

The Editorial Office informs the MDPI Accounts Department on the APC for each paper. The APC can no longer be changed once a paper has been accepted for publication. Therefore, please confirm the APC with your Assigned Editor during the APC confirmation stage (including any applicable discount).

8. I have already paid my invoice, but it is still shown as outstanding on the MDPI platform/I have received a payment reminder. What should I do?

Please note that it may take several days for a bank transfer to be registered. Please make sure to include the invoice ID in the payment (e.g. invoice ID: journalname-123456). If your payment was not confirmed, please send a valid proof of payment to .

9. What if I accidentally pay more or less than the invoiced amount?

If your initial payment was incomplete (e.g. not including the 5% fee for PayPal payments), another invoice will be issued to you for the remaining amount.

In case you accidentally pay more than invoiced by MDPI, please contact us at and we will refund the overpaid amount, minus any bank or transaction charges.

10. I would like to prepay/allocate funds for future paper(s), is this possible?

MDPI provides an option for payment in advance if the customer’s budget funds may expire before the final decision of the paper is provided. Such agreements should be organized with the Editorial Office of the relevant Journal. The MDPI Accounts Department will send an invoice (proforma) in advance if requested. Please note that any advance payment will not affect the final decision as to whether an article is accepted for publication.

Please contact and indicate in which journal you would like to submit a paper and provide your billing address.

11. My prepaid paper has been rejected and I want a refund. How can I proceed?

If the paper is rejected, MDPI will issue a refund upon request after deducting the bank fees, or you could choose to keep the amount as pre-payment for another publication.

12. How can I apply for a refund of the APC if my paper is retracted?

Please note that APCs will not be refunded due to the retraction of an article.

13. How can I apply for a refund of the APC if my paper is accepted?

If a paper has been accepted the payment is non-refundable. In the event that a manuscript is withdrawn by author request after it has been accepted any payment made may only be used as credit on a future submission.

14. Do I have to pay if my manuscript is rejected?

No. MDPI only sends the invoice for article processing charges (APCs) if a manuscript has been accepted for publication. The acceptance of a manuscript is based on the outcome of the peer-review procedure. The final decision as to whether a manuscript will be accepted for publication or rejected is made by an external editor (usually the Editor-in-Chief of a journal or the Guest Editor of a Special Issue) generally based on scientific merit.

15. Do you accept Purchase Orders?

Yes, we accept Purchase Orders (PO’s). Please send your PO’s to and indicate the invoice/manuscript ID in the subject line.

16. Do you accept E-invoices?

We are already using several platforms for e-invoicing. It is mandatory to send all the required information or codes per e-mail, otherwise we will not be able to provide the correct invoice. We use a B2B Router platform, Chorus Pro (for French subjects) and Coupa.

17. I have sent you a request regarding vendor registration/required documentation/etc. but I have not received a reply yet.

It is important to indicate the invoice/manuscript ID in the subject line, in case a reply is needed.

18. Will any VAT/Sales Tax be applied to APCs?

All quoted APCs are exclusive of VAT. With the exception of customers residing in Switzerland or Japan, no VAT will be added to invoices. Authors should account for the VAT in their country under the reverse charge mechanism, whereby the recipient of a service from a foreign company pays the VAT directly to the local tax office. Please check with your institution for guidance on local VAT.

19. Are residents in Japan required to pay the consumption tax?

The Japanese Consumption Tax (JCT) at the rate set by the Japanese government shall be added to the invoices for residents in Japan.

20. My question is not on the list.

Please contact MDPI Accounts Department for further questions. If your paper has already been submitted, please indicate your invoice/manuscript ID.

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