Late Bottled Vintage (often referred to simply as LBV) was originally wine that had been destined for bottling as Vintage Port, but due to lack of demand was left in the barrel for rather longer than had been planned. Over time it has become two distinct styles of wine, both of them bottled between four and six years after the vintage, but one style is fined and filtered prior to bottling while the other is not.

The filtered wine has the advantage of being ready to drink without decanting, and is bottled in a stoppered bottle that can be easily resealed. However many wine experts feel that this convenience comes at a price and believe that the filtration process strips out much of the character of the wine.

Unfiltered wines are bottled with conventional corks and need to be decanted. Recent bottlings are identified by the label wording 'Unfiltered' or 'Bottle matured' (or both). Prior to the 2002 regulations, this style was often marketed as 'Traditional', a description that is no longer permitted.

If in doubt, a prospective purchaser can check the cork, and examine the top of the bottle to see if there is a stopper underneath the capsule; the serrated edge of a stopper is usually visible, or can be detected with a thumbnail. LBV is intended to provide some of the experience of drinking a Vintage Port but without the decade-long wait of bottle aging. To a limited extent it succeeds, as the extra years of oxidative aging in barrel does mature the wine more quickly.

Typically ready to drink when released, LBV ports are the product of a single year's harvest and tend to be lighter bodied than a vintage port. Filtered LBVs do not improve significantly with age, whereas the unfiltered wines will usually be improved by a few extra years in the bottle. Since 2002, bottles that carry the words 'Bottle Matured' must have enjoyed at least three years of bottle maturation prior to release.