A continuous identifier is useful only when everyone can connect it to the same source page. Before numbering a document batch, agree on its file order and preserve that manifest. A correct-looking sequence cannot explain an undocumented change in which document came first.

Use fictional PDF copies in Acrobat Pro: A contains two pages and B contains three. Give each page distinctive harmless content, and record the input names and page counts before starting.

Fix the batch order and output location

Choose Edit > More > Bates numbering > Add. Add the two files, set Output Options to a separate destination, and arrange A before B using Move Up or Move Down. Confirm the list before proceeding to the header/footer settings.

Choose the placement box, select Insert Bates Number, set three digits and start at 101. In this order, A receives 101–102 and B receives 103–105. Reversing the files would assign B 101–103 and A 104–105.

Acrobat supports digit counts from 3 to 15. Protected or encrypted files and some form types are unsupported; resolve an input problem with the document owner rather than attempting to bypass protection.

Verify page identity across the boundary

Inspect the last page of A and first page of B together. Record each output filename, its local page position, visible identifier and distinctive content. Then check the first and final identifiers of the entire batch against the manifest.

Keep any reversed-order experiment in a clearly separate test folder. Do not mix its outputs with the accepted batch simply because both have uninterrupted numbers. The manifest should make it possible to tell which experiment produced each file.

For the final handover, retain the source copies, agreed order and output mapping together. This is a document-organization check; any requirements for a particular filing or submission must be established separately with the responsible recipient.

Sources: Adobe: Bates numbering.