If biological material deposited according to Rule 31 ceases to be available from the recognised depositary institution, an interruption in availability shall be deemed not to have occurred if:[Rule 34; ]

The non-availability may occur because, for example:

In either case (a) or (b) above, a new deposit must be made within three months of the depositor's being notified of the non-availability of the organism by the depositary institution (Art. 4(1)(d) Budapest Treaty). This is subject to the exception, where:

In this exceptional case, the new deposit must be made within three months from the date of the said publication by the International Bureau (Art. 4(1)(e) Budapest Treaty).

If, however, the original deposit was not made under the Budapest Treaty, but rather at a depositary institution recognised by the EPO by virtue of a bilateral agreement, the above-mentioned six-month period is calculated from the date when the EPO publishes the fact that the depositary institution in question is no longer qualified to accept deposits of the biological material in question under that bilateral agreement.