This is all quite interesting in that the US embassy website in Nicaragua points out this for non-tourist travel which I think is aimed at NGOs and maybe reporters (I can't imagine business people nor investors will be impressed). The link to the Nicaraguan immigration site (below) linked to from the US web site says (English translated) "for purposes other than tourism" and that link works, but there is no mention of tourism/non-tourism at the web page of migob.com.ni . In fact there are two links (e.g a link that says not required for tourism and a link that is silent on tourism) that go to the same page, where tourism (or not) is not mentioned at all.
I wrote to their immigration department as to if this is required for tourists. Since it has not been an issue for 2 years it probably is not mandatory but they have posted what they call the "Summer of Love Plan 2019" which just reiterates all this (minus saying a thing about tourists, again) on March 8 of this year, on their web site. I think they hope for boatloads of tourists this year despite about a 50% decline in tourists due to tourist perception of extreme risks, which really is not the case and has not been for almost a year.
Even before the issues that concern people after last April, the lines at immigration rarely took more than 15 or 20 minutes and that was only when a flight on AA plus one from Copa or Spirit all arrived at the same time.
-----------------Reference Material -----------------------------
From the State Department website regarding entry requirements:
For
visitors other than tourists, the Nicaraguan government recommends that you pre-register your trip by following the instructions available on the
Nicaraguan immigration website (in Spanish only). See
our website for additional information.
(Ed: their link was posted in August 2017)
From the US embassy, Nicaragua, web site which I must say is easier to follow than any version of the Nicaraguan web site (dated August 2017 also):
MESSAGE FOR U.S. CITIZENS: PRE-NOTIFICATION OF NON-TOURIST TRAVEL TO NICARAGUA.The Nicaraguan government has i
ntroduced a pre-notification process for all non-tourist travel to Nicaragua. Nicaraguan officials have stated that the pre-notification process is highly recommended. They explained that travelers with pre-notification will pass through migration controls quicker than those without it. According to Nicaraguan officials, the pre-notification process allows them to properly allocate border control resources to align with the expected number of travelers at a given time, day, and location.
Pre-notification should occur at least seven days in advance of planned travel to Nicaragua, following the instructions provided in Spanish at
https://www.migob.gob.ni/migracion/tramites/solicitud-de-ingreso-ordenado-y-seguro-de-visitantes-invitados-por-motivos-diferentes-al-turismo/. Nicaraguan officials stated that the form available on that webpage is a suggested format only, and that pre-notifications must at least include information from the middle two paragraphs of the four-paragraph form
(ed: the 1st paragraph of the form is a request from a sponsor, the 2nd and 3rd paragraphs provide information such as who, when and how long and what the purpose is of the visit, and the 4th is contact information for your sponsor . Also it appears the sponsor if there is one, has to submit the form, not the traveler) . Travelers do not have to wait for a reply before proceeding with their travel plans.