In January, the discount is 14%, off the base rate only.

A typical bill in 2010 for a solar lot at El Dorado Ranch is 713.56 pesos, plus 107.03 pesos for the 15% "sports facilities" surcharge, less 99.89 pesos for the 14% early payment discount, giving a net payable of 721 pesos (around US$ 57).

In many cases in El Dorado these amounts are a couple of hundred pesos less than last year because the HOA has successfully renegotiated the way that lots are valued, to exclude non-constructible land such as roadways.

In February, the discount drops to 10%, and it drops further to 5% in March.

You can check your property tax at the Mexicali impuesto predial website, although the site is often broken. It's in both Spanish and English. You'll need your clave catastral (property id), which is on previous property tax bills.

In El Dorado, the HOA office in the main gatehouse by the Pemex can help you convert from a lot number to the clave catastral (property id), and there are also documents on the Ed Dorado web site that have the same information.

In January (at least), you can pay the property tax directly to a representative from the municipality at the El Dorado HOA office. If you're in San Felipe (and have a property in El Dorado) this is by far the simplest option. Paying it in person is 2 pesos more than the amount shown online, as a 2 peso donation to the Red Cross is automatically added.

You can also pay it online at the Mexicali website above. If you do pay online, be sure to turn off any pop-up blockers on your browser to make it more likely (but not certain) that you will see a receipt (which you should print, there is no way to recover it later). Also bear in mind it's a transaction within Mexico so a credit card issued in another country such as the US may automatically block it, and very likely charge a foreign transaction fee. There are reports that Mexicali may add a 3.5% fee as well.

Alternatively, the main property tax office in San Felipe is in the municipal building next to the fire station and across from the post office, on Av. Mar Blanco Sur (I think that's the turning off Chetumal - the main road north from San Felipe - with Banamex on the corner, somebody correct me please if I'm wrong).