The records in this series resulted from an Exchequer Order of November 1564 requiring all customs officials in the various ports of England and Wales thenceforth to make their entries in blank books issued by the Exchequer.
The books are of three kinds:
Entry books of the collectors and other officials, recording the details of cockets issued as receipts for the payment of the various duties on imports and exports;
Entry books of searchers, waiters and other officials who were concerned with shipping movements and the inspection of cargoes, not with the collection of duties; and
Coasting books, which record the issue and return of certificates for the transit of goods by coast from one English port to another. The certificate stated that the shipper had entered into bonds to unlade only at another port within the realm.
Each entry in a Port Book generally contains:
the name of the ship and its master;
the names of the merchants (sometimes giving the merchant's mark) and whether they were aliens;
date on which duty was paid (not the date of arrival or unloading);
a description of their goods;
the amount of duties paid (in the entry books of the collectors);
the ship's destination or port to which it was sailing next.
After 1600 few books omit details of the places to and from which shipments were made.
See also the Mainland English, Scottish and Irish Outport records: CUST