Although not especially busy, the land border with Mexico is a popular entry point into Belize and relatively straightforward.
Many travellers make the journey by bus from Cancun, the Riviera Maya or Tulum by bus, crossing over the border into Belize and then continuing south to Belize City and thence on to various other destinations,
My own experience was somewhat different in that I had spent a few days in Mexico City. With no direct flights between Mexico City and Belize I therefore had to fly to Chetumal and then cross over to Belize. I had also pre-booked private transport in advance.
So, having arrived at Chetumal airport at just after 2pm, my driver was there to meet us (there were 4 in our party). Oddly however, we were not able to use his van from the airport but had to jump in a local taxi, which he had arranged, before transferring to his van just down the road.
From Chetumal airport to the Belize border only takes around 10 minutes’ drive at the most. On arrival, we had to get out of the car and hand over our passports to Mexican immigration and pay the departure tax of 900 pesos (£1 = 20 pesos approximately). That took no time at all and we then got back into the van and drove across into no-mans-land where we again got out of the van, this time with our luggage, and proceeded to Belize immigration where we were given simple entry forms to complete. The immigration official took one part of this form and handed back the other which we were told we would need to present when leaving Belize.
Having had our passports stamped, there was a very cursory check of our bags by the customs officials and then that was it. Our driver was waiting for us on the other side and it was then a short drive of, again, around 10 minutes to Belize’s northern-most town, Corozal, and our accommodation for the night.
It is worth noting that our onward destination was Caye Ambergris which we flew to the next morning from Corozal’s tiny airport on the outskirts of town. However, there is also a daily afternoon boat service from Chetumal to Caye Ambergris, another option for crossing from Mexico to Belize.