In 1703 the rates were raised mainly in order to provide funds to meet the expenses of the wars of Louis XIV. Two reasons were assigned: the necessity for increased revenue, and the necessity for remedying certain defects in the existing rates, in regard to the distances and the progression of weight—the charges should be proportionate to the actual distance traversed by the couriers; and the existing rate of charge for ounce letters was therefore unjust, because it required at least six single letters to make up a weight of 1 ounce.[188]
As a matter of fact, the new rates fixed in 1703 did not vary exactly with distance. The number of zones was doubled, and the distances were reckoned according to the number of stages, and the routes actually followed by the couriers. The charge for a single letter varied from 3 to 10 sous.
These rates remained in force until 1759, when a variety of causes led to a further increase of rates. The Seven Years' War had made an increase of taxation necessary; there had been a depreciation of money, and an increase in the cost of all commodities, which had resulted in an increase of the expenses of conducting the posts. Under the tariff of 1759 the eight zones of 1703 were maintained, and the rate for single letters varied from 4 to 14 sous, with an additional rate of 1 sou for all letters enclosed in an envelope. The principle of charge according to weight was introduced for letters weighing less than 1 ounce, which up to this time had been charged only according to the number of sheets. Double letters weighing more than ¼ ounce and less than ½ ounce, were rated at 7 sous for the first zone, and for the other zones a "rate 2 sous less than the ordinary rate for double letters." Packets were charged by the ounce, and the rate per ounce was four times that for a single letter. As with the tariff of 1703, distances were calculated according to the route actually followed by the couriers.
No further modification of the rates was made until after the Revolution. The lease of the posts was due to expire
on the 31st December 1791, and it was decided that the Legislature should rectify the tariff before the date at which the posts would revert to the State.[189] A rectification was accordingly announced by the decrees of the 17th-22nd August 1791. This revision slightly increased the rates of 1759. The initial rate of 4 sous for single letters circulating within the same département was retained; the rate for letters circulating in the same arrondissement was fixed at 3 sous; between départements the rate was increased, and varied from 5 to 15 sous, according to distance of transmission; and the number of zones was increased to eleven.[190]
Distances were no longer to be reckoned according to the length of the route actually traversed, but from point to point as the crow flies. The points were not, however, the actual points of posting and of delivery. In each department a point was fixed upon, and the rate for all letters posted or delivered in the département was calculated as from that point; so that for a given weight the same rate was payable on all letters exchanged between the same two départements. This system, though comprising a very large number of rates, was much simpler than the earlier systems. Any one town or village now had only 82 rates for each step in the scale of rates, whereas under the previous system a special rate must be calculated for every other town or village in France. To assist the application of this tariff, a map showing the central point fixed upon for each of the 82 départements, and the distances from each central point to all others, was prepared and supplied to every post office in France.
The tariff of 1791 also abolished the method of charge according to the number of sheets, and substituted the simpler method of charge according to weight alone. The maximum weight for a single letter was fixed at ¼ ounce, and for heavier letters the rates were—
| From | ¼ | oz. to | ½ | oz. | 1½ times | the rate for a single letter |
| " | ½ | " | ¾ | " | twice | " |
| " | ¾ | " | 1 | " | 3 times | " |
| " | 1 | " | 1¼ | " | 4 times | " |
and so on, the increase being one single rate for each
¼ ounce increase of weight. The rate for letters circulating within the same town remained 2 sous an ounce.