Anharmonic force fields and ro-vibrational spectroscopic properties of BF3 and CF3+ have been 3 investigated, using the coupled cluster method with single and double substitutions augmented by a perturbative estimate of triple excitations [CCSD(T)] with a basis set of 120 contracted Gaussian-type orbitals (cGTOs). A complete set of re-vibrational spectroscopic constants for each species has been calculated using second-order perturbation theory. For BF3 the CCSD(T) equilibrium bond distance is larger than the experimental value by 0.0058 Angstrom, and the fundamental frequencies are within 5 cm(-1) of experiment, except for v(3), which shows a deviation of 16 cm (-1). The CCSD(T) method yields vibration-rotation interaction constants alpha(e) in excellent cm agreement with available experimental values (within 3 MHz). The CCSD(T) bond distance of CF3+ is 1.2305 Angstrom with a basis set of 220 cGTOs, which is corrected to 1.2272 Angstrom by applying a correction derived from the identical level of calculation on BF3. The fundamental frequencies v(1), v(2), v(3), v(4) for CF3+ are predicted to be 1044 cm(-1), 813 cm(-1), 1683 cm(-1), and 593 cm(-1), respectively.