If the publication fee exceeds the limit of 1680 EUR (excl. VAT) a pro rata funding is impossible. We recommend that authors apply for a waiver or reduction in fees.
No. But make sure that invoices from European countries other than Germany give the price without value-added tax.
If an APC exceeds the 1680 Euro limit by a small amount and if that overrun is caused only by exchange-rate fluctuation, the article will not be excluded from funding.