Can one lie to a non Jewish person? If the answer is Yes, are there certain cases where you can't?
Deceiving anyone including a non-Jew is strictly forbidden. Even if the non-Jew suffers no loss.And even if the deception is not explicit lying.
The Gemora (Chullin 94A)says: “Shmuel says, it is forbidden to deceive people, even non-Jews
One practical example given there is sending non-kosher food to a non-Jew who thinks it is kosher. Although it should make no difference to him it is still forbidden deception.
Another example the Gemara there gives is that a non-Jew helped them pass over a bridge, and his assistant paid the non-Jew with a non-kosher chicken. Shmuel was upset with the shamash, because the non-Jew would think the chicken was kosher and be deceived.
We explicitly paskan this way in Shulchan Aruch Chosen Mishpat 228:6
As a general rule, you cannot lie to any human. "Nothing but the truth".
However, the rule of "all the truth" isn't always applicable vis a vis non-Jews.
The Kitzur Shulchan Aruch says in סימן קפב - הלכות גנבה וגזלה:
אָסוּר לִגְזוֹל אוֹ לִגְנוֹב אֲפִלּוּ כָּל שֶׁהוּא, בֵּין מִיִשְֹרָאֵל בֵּין מִגּוֹי. אִיתָא בְּתַנָּא דְבֵי אֵלִיָהוּ, מַעֲשֶׂה בְּאֶחָד שֶׁסִּפֵּר לִי, שֶׁעָשָׂה עַוְלָה לַגּוֹי בִּמְדִידַת הַתְּמָרִים שֶׁמָּכַר לוֹ, וְאַחַר כָּךְ קָנָה בְּכָל הַמָּעוֹת שֶׁמֶן, וְנִשְׁבַּר הַכַּד וְנִשְׁפַּךְ הַשֶׁמֶן. וְאָמַרְתִּי, בָּרוךְ הַמָּקוֹם שֶׁאֵין לְפָנָיו מַשּׂוֹא פָּנִים. הַכָּתוּב אוֹמֵר, לֹא תַעֲשׂק אֶת רֵעֲךָ וְלֹא תִגְזֹל. וְגֵזֶל הַנָכְרִי, גָּזֵל. It is forbidden to rob or to steal even an article of trivial value from a Jew or from a non-Jew. It is recorded in Tanna Devei Eliyohu: It happened that a man told me [Eliyah] that he had wronged a non-Jew in measuring dates that he sold to him. Thereafter, he bought oil with all that money and the jug broke and the oil spilled. I said, "Blessed is the Omnipotent that shows no favoritism." The Torah says, "Do not cheat your fellow, nor rob him," and robbery of a non-Jew also constitutes robbery.
However, there are cases where one need not provide more information than requested, thereby cheating the non-Jew out of what is rightfully his, with the cavaet that there's no chance of him ever discovering it and that one does not lie and that it's not a business deal.
The Kitzur continues:
אָסוּר לַעֲשׂק אֶת חֲבֵרוֹ אֲפִלּוּ כָּל שֶׁהוּא, שֶׁנֶּאֱמַר, לֹא תַעֲשׂק אֶת רֵעֲךָ. וְאֵיזֶהוּ עושֵׁק. זֶה שֶׁבָּא מָמוֹן חֲבֵרוֹ לְיָדוֹ בִּרְצוֹן חֲבֵרוֹ, כְּגוֹן שֶׁיֵשׁ לוֹ בְיָדוֹ הַלְוָאָה אוֹ שְׂכִירוּת, וְאֵינוֹ רוֹצֶה לְשַׁלֵּם לוֹ, אוֹ שֶׁדּוֹחֵהוּ בְּלֵךְ וָשׁוּב, לֵךְ וָשׁוּב. וְכֵיוָן דִּכְתִיב רֵעֲךָ, אֵינוֹ אָסוּר בַּגּוֹי. וְהוּא שֶׁאֵין חִלוּל הַשֵּׁם בַּדָּבָר, כְּגוֹן שֶׁלָּוָה מִגּוֹי וָמֵת, רַשַׁאי לְכַחֵשׁ לִבְנוֹ, שֶׁאֵינוֹ יוֹדֵעַ בְּבֵרוּר שֶׁהוּא מְשַׁקֵּר. אֲבָל כְּשֶׁהַגּוֹי יוֹדֵעַ שֶׁהוּא מְשַּׁקֵּר, אָסוּר, מִפְּנֵי חִלוּל הַשֵּׁם. וְאַף בְּמָקוֹם שֶׁאֵינוֹ יוֹדֵעַ, אֵינוֹ רַשַׁאי אֶלָּא לְהַפְקִיעַ הַלְוָאָתוֹ אוֹ שְׁאָר חוֹב שֶׁהוּא חַיָב לוֹ. אֲבָל חֵפֶץ שֶׁהוּא בְעָיִן, אָסוּר לִכְפֹּר, שֶׁהֲרֵי זֶה הֲוֵי גָזֵל מַמָּשׁ. וְלֹא עוֹד, אֶלָּא אֲפִלּוּ קָנָה מִמֶּנוּ חֵפֶץ, אָסוּר לְהַטְעוֹת אוֹתוֹ בְּחֶשְׁבּוֹן בִּנְתִינַת הַמָּעוֹת, כְּמוֹ שֶׁנֶּאֱמַר, וְחִשַּׁב עִם קוֹנֵהוּ, דְּמַיְרֵי בַּגּוֹי, שֶׁהֲרֵי אֵינוֹ מַקְנֶה לוֹ הַחֵפֶץ אֶלָּא בְּעַד הַסְּכוּם שֶהִשְׁתַּוּוּ. וְהַמַּטְעֵהוּ בְּחֶשְׁבּוֹן הַמָּעוֹת, הֲרֵי זֶה כְּגוֹנֵב אֶת הַחֵפֶץ וְלֹא כְּמַפְקִיעַ חוֹבוֹ. וַאֲפִלּוּ גְנֵבַת דַּעַת שֶׁאֵין בָּהּ חֶסְרוֹן מָעוֹת, אָסוּר בְּמַשָּׂא וּמַתָּן, כְּמוֹ שֶׁכָּתַבְתִּי בְסִימָן סג. וּמִכָּל מָקוֹם אִם הַגּוֹי טָעָה בְעַצְמוֹ, מֻתָּר אִם לֹא יִהְיֶה חִלוּל הַשֵׁם בַּדָּבָר, שֶׁלֹּא יִוָּדַע לוֹ. וְנָכוֹן שֶׁיֹּאמַר לוֹ הַיִשְֹרָאֵל, רְאֵה שֶעַל חֶשְׁבּוֹנְךָ אֲנִי סוֹמֵךְ.
It is forbidden to cheat your fellow even in the slightest degree, as it is said, "Do not cheat your neighbor." What is cheating? If your neighbor's money comes into your possession with his consent; for example, if he lent you money, or you owe him wages (or rent), and you do not wish to pay him, or you put him off by saying, "Go," "and return [later]." Since the verse states: your [Jewish] neighbor, it is not forbidden to do so with a non-Jew. This is true only if this will not cause the Name of God to be desecrated; for example if you borrowed from a non-Jew and he died, it is permitted to deny the loan to his son, because he does not know for sure that you are lying. However, if the non-Jew knows you are lying, it is forbidden because of the desecration of God's Name. And even if the son is not sure, it is only permitted to deny a loan, or any other such debt you owed him. If you have in your possession an article you received from a non-Jew which is intact, you are forbidden to deny it, for this constitutes actual robbery. Moreover, even if you buy something from a non-Jew, you are forbidden to fool him in counting out the money, as it is said, "And he shall reckon with his buyer,"4 which refers to a non-Jew. For he is only conveying the article to you in consideration of the sum agreed upon, and if you fool him in the payment, it is tantamount to stealing the article, and not merely denying a debt. Even deception not involving any loss of money is forbidden in business dealing, as was explained in Chapter 63. Nevertheless, if the non-Jew makes a mistake, it is permitted to benefit from it, provided there will be no desecration of God's Name, [for example] in such a case where he remains unaware of his mistake. It is best to say to him, "I am relying on your estimate or your bill."