Tithe maps are important as the first systematic mapping survey of most of the land in England and Wales, as compared to estate maps which were for limited private use. They were made before the Ordnance Survey produced the large scale 25 inch to the mile series of maps.
Parish boundaries in southern England may reflect not only the boundaries of very old ecclesiastical units but possibly even older estate boundaries. Tithe maps can show an 'island' of one parish inside another, which may reflect a division between two estates. These 'islands' were assimilated into the surrounding parishes in the 19th century and so may have disappeared before the 1st series Ordnance Survey maps were surveyed. The Hambledon Tithe Map is an example (ref 864/1/77).
Tithe field numbers may be found identifying areas of land on 19th century title deeds.
In contrast to the general uniformity of tithe apportionments, tithe maps vary greatly in accuracy, scale and size.
The landowners were responsible for paying for both the tithe map and the apportionment, and as plotting each new map on a standard scale was expensive, the Tithe Amendment Act 1837 allowed for two grades of map.
The colour pink on tithe maps is used to indicate an inhabited building. Outbuildings are coloured grey.
Scales of Surrey tithe maps vary between 1.5 and 12 chains to 1 inch, with about 68% within the recommended scale range of between 3 to 4 chains to 1 inch. (20 chains = 1/4 mile)
The legislation stipulated that after the map and apportionment had been ratified by the Tithe Commissioners they would be displayed in the parish. They would then be returned, so that two further copies could be made, one for the diocesan registry and one for the incumbent of the parish. The Public Record Office has a complete set of the Commissioners' maps. The diocesan and parish copies are likely to be found in local record offices.
Lands previously exonerated from tithe by enclosure were usually not surveyed.
Some land had never been titheable, such as land which belonged to certain religious houses. Examples in Surrey are: Wanborough, St Mary Bermondsey, Churt - a perpetual curacy, St Peter Newington - a district chapelry.
Non-titheable land deemed to be unproductive could be excluded; commons and roads were also excluded.
All woodland in the weald in Surrey, Sussex and Kent was tithe free.
In Surrey 32% of tithe maps are sealed as first-class, and these seem to be concentrated in a west-east band along the North Downs. The tithe maps of Croydon, Dorking and Epsom are unusual in being first-class maps of urban areas.
Second-class maps are extremely variable in quality. Some were original surveys, others little more than topographical sketches or copies of slightly earlier maps. Some made elaborate use of colour to distinguish different properties, tithe free areas or land use, while others gave no such detail. With second-class maps the date of the survey is usually uncertain. In Surrey the tithe map of Lingfield is a copy of an 1816 map and the tithe map of Wimbledon is a copy of an 1838 map.
Even amongst first-class maps there is a great deal of variation in scale and content. Significant variations have been shown between different versions of the same map.