There was a whole infrastructure for this, reporting to the Minister of the Treasury, and making up the 3rd Section of his ministry.The handling of all ready-cash funds and payments made by same were supposed to be done by "payeurs", both for civilian and military government expense.
There were 4 payeurs-général de la résorerie (war/army, navy/colonies, bonds/pensions and "other") each with a primier commissaire as an assistant. These held rank considered equal to a général de brigade.
There was also a Treasury of the Crown – for Napoléon's family money.
Reporting to the Treasurer General of the Crown, there were 14 payeurs-de-la-couronne allocated at installations owned by the imperial family, one payeur de la garde impériale, one payeur du conseil d'état, and one currency exchange specialist. Lastly, there was a Treasury of "Domaine Extraordinaire" – for extortions from conquored lands, private expense of Napoléon, gifts to his supporters. The payeurs for this service were not usually publically gazetted due to the sensitive nature of their work
Back now to the regular treasury …. there were several payeurs-spéciaux (Engineering, Public Works, Invalides, Police, War Aministration, Finance Ministry, Justice Ministry and Ministry of Froegin Affairs) Each civilian département had a payeur-départemental, supported by a adjoint or préposé du payeur in each of the major towns. If the capital of the department was also the headquarters of a military division, the departmental payeur was also responsible as a payeur-divisionaire. There were 16 payeurs-de-la marine at the major ports. There was also a "payeur-général de l'armée" for each army and a "payeur-général de la garde". In 1812 there was also a "payeur-particulier de la maison de S.M.", baron Guillaume-Joseph Peyrusse (1776-1860). These all held rank and wre paid considered equal ("assimilé") to colonel or adjudant-commandant.
Peyrusse left us his letters :
Lettres inédites de Guillaume Peyrusse "à son frère André" 1809–1814
ed. Léon Pelissier
Paris Plon, 1894
Lettres inédites de Guillaume Peyrusse
His habit :
The lower ranking payeurs had less embroidery. They were armed with sabres when on campaign.
"frac droit, bleu, avec boutons à l'aigle, basques retroussées; culottes blanches, bottes; pantalon bleu, chapeau à claque; grand manteau, sabre"
The baron Peyrusse reports that he had an extra detachment of six specially chosen fusiliers de la garde to protect his cash boxes.
The payeur-général de l'armée was Bernard. The payeur-général de la garde was Baudeuf (tué à Smolensk)
At each corps there was a payeur-principal, rank considered equal to chef de bataillon or d'escadron or commandant.
Each of the above would have one or more payeurs-adjoint or préposés, and several employées.
What they lacked was their own transport – this was provided by the intendence or was hired locally – it could be anything.
The gendarmes à cheval detachment was their typical guards. But others could be substituted or augmented.
See :
Les payeurs d'armées
par le payeur principal Frémont
Paris, Plon, 1906.
link
So much for the treasury officials.
In each regiment there was a lieutenant officier payeur with a lockbox. He was attached to the 1er bataillon and rode the "caisson pour le transport des papiers – intended to be a regular artillery caisson adapted intenrally to carry papers and drawn by 2 horses. The caporal garde-magazine would be responsible for posting a local guard.